The ultimate guide to building a mobile app
Got a great idea for an app? Need a new way to grow your business? We tell you everything you need to know about building a mobile app in 2020.
Kotlin is a popular and powerful open-source programming language. It is the official language of Android development, allowing developers to create sophisticated, innovative apps. Kotlin simplifies and speeds up development, allowing ambitious projects to be implemented faster, with fewer lines of code. This makes it an attractive option for clients looking to build a highly functional app or website quickly and efficiently.
Kotlin Developers bring valuable experience and expertise to any project they take on, allowing clients to get the most out of their investment. They are experienced in app architecture and development, making sure that client’s apps function exactly as desired. They also have excellent problem-solving skills, ensuring any issue is quickly resolved. In addition, their understanding of the Kotlin language makes working with this powerful tool more efficient and effective for clients.
Here's some projects that our expert Kotlin Developer made real:
At Freelancer.com we want our clients to know that their projects will be handled expertly by professionals with extensive experience in building with the Kotlin language. We can provide you with an experienced Kotlin Developer who can make your ambitious projects a reality in record time. Together you can bring your plans to life quickly and efficiently, allowing you to reap the rewards of our collaboration as soon as possible. If you're interested in taking advantage of our expertise in the field of Kotlin development then please do not hesitate to post your project today so that one of our professionals can help bring your plans to life!
From 55,262 reviews, clients rate our Kotlin Developers 4.9 out of 5 stars.Kotlin is a popular and powerful open-source programming language. It is the official language of Android development, allowing developers to create sophisticated, innovative apps. Kotlin simplifies and speeds up development, allowing ambitious projects to be implemented faster, with fewer lines of code. This makes it an attractive option for clients looking to build a highly functional app or website quickly and efficiently.
Kotlin Developers bring valuable experience and expertise to any project they take on, allowing clients to get the most out of their investment. They are experienced in app architecture and development, making sure that client’s apps function exactly as desired. They also have excellent problem-solving skills, ensuring any issue is quickly resolved. In addition, their understanding of the Kotlin language makes working with this powerful tool more efficient and effective for clients.
Here's some projects that our expert Kotlin Developer made real:
At Freelancer.com we want our clients to know that their projects will be handled expertly by professionals with extensive experience in building with the Kotlin language. We can provide you with an experienced Kotlin Developer who can make your ambitious projects a reality in record time. Together you can bring your plans to life quickly and efficiently, allowing you to reap the rewards of our collaboration as soon as possible. If you're interested in taking advantage of our expertise in the field of Kotlin development then please do not hesitate to post your project today so that one of our professionals can help bring your plans to life!
From 55,262 reviews, clients rate our Kotlin Developers 4.9 out of 5 stars.I run a clothing retail shop and I’m ready to replace my paper spreadsheets with a single Android app that puts all of my numbers in one place. The cornerstone of the project is powerful analytics: I want to see trends, charts and drill-downs at a tap, so the data architecture needs to be built with future dashboards in mind. Core scope • Sales tracking – the app must record each sale on the spot and immediately feed two ready-made views: a daily sales report and product-wise sales breakdown. • Expense management – for now I only need to log and analyse utility bills, but the design should leave room to add inventory costs or salaries later without rewriting the database. • Simple form-based data entry – cashiers or I should be able to add a sa...
I’m creating “Crois moi c'est possible”, a brand-new social networking experience that will live exclusively on Android. The goal is to give users an intuitive space to connect, share photos and short videos, chat in real time, and receive instant push notifications—everything they expect from a modern community app, wrapped in a clean Material Design interface. You’ll take the lead on end-to-end Android development, so solid Kotlin or Java skills are essential. A cloud back-end (Firebase, Supabase, or a solution you recommend) will handle authentication, media storage, and real-time data. I’m keen on scalable architecture, readable code, and smooth UI/UX transitions; if you excel at Jetpack Compose, even better. Deliverables • Fully functi...
I’m ready to turn my concept for a dedicated social-media Android app into a fully functioning product. The project is strictly mobile app development for the Android platform—no iOS component is planned at this stage—so your experience with Kotlin or Java, Android Studio, Firebase (or an equivalent real-time back end), and clean Material Design guidelines will be critical. Core idea The app should allow users to create profiles, share posts (text, images, short video), follow others, and receive real-time notifications. Think lightweight, fast, and intuitive rather than a bloated “all-in-one” network. A smooth onboarding flow, secure authentication, and an easily scrollable home feed are my immediate priorities; messaging and advanced discovery features can ...
I need an intermediate-level mobile application created from scratch for both iOS and Android. The core objective is to hand me a fully functional, well-structured codebase along with the compiled builds ready to submit to the App Store and Google Play. You are free to choose the most efficient toolchain—whether that is Flutter, React Native, Swift + Kotlin, or another framework—as long as performance and maintainability remain a priority. I will supply the UI wireframes and any required brand assets; you will turn those into a polished, responsive interface, wire up the back-end endpoints I provide, and ensure the finished product passes standard QA checks on real devices for each platform. By project close I expect the complete source code, build instructions, and a brief...
Build a full-featured voice chat application that runs smoothly on Android and ships with the complete source code. Core features to implement • Phone-number verification as the only login method, followed by secure session handling. • User profiles that can be expanded later (start with photo, name, bio, interests). • Public chat rooms with high-quality, low-latency voice. • One-to-one private voice calls plus real-time text messaging. • Push notifications for invites, messages, follow requests, wallet events, and admin broadcasts. • In-app wallet able to hold balances, process top-ups, and trigger withdrawal requests; history must be visible to the user and editable from the back office. • Web-based admin panel to manage users, rooms, trans...
The project involves building a native Android application from the ground up. I already clarified that the scope is specifically Mobile app development and, at this stage, I want to target Android only. Key needs • A clean, intuitive user interface that follows current Android design guidelines. • Robust, well-structured Kotlin or Java code (whichever you are most comfortable with) that is easy to maintain and extend. • All standard mobile essentials: responsive layouts for multiple screen sizes, offline handling where appropriate, and thoughtful permission management. • End-to-end support—planning, UI/UX, coding, testing, and a guided hand-off for Google Play deployment. Deliverables 1. Full Android Studio project with readable source code. 2. Sign...
I’m planning a clean, intuitive navigation app that runs natively on both iOS and Android. The core experience should be the familiar 2-D map interface with smooth pinch-zoom and tilt, focused on one key feature: reliable turn-by-turn directions. My priority is accuracy and speed. When a user selects a destination, the route should calculate quickly, announce upcoming turns clearly (voice + on-screen), and recalculate instantly if they deviate. I’m happy to leverage MapKit, Google Maps SDK, Mapbox, or another solid framework—whichever you feel will give the best licensing terms and performance on both platforms. While real-time traffic and fully offline map packs aren’t required for the first release, I’d like the architecture to leave room for those modul...
I need a single Android application that combines two core utilities: an efficient memory optimizer and an antivirus module. On the cleaning side, the app should intelligently free RAM, close unnecessary background processes, and provide clear before-and-after stats so users see how much memory was reclaimed. The process must be quick, unobtrusive, and light on battery. For safety, I want a built-in antivirus engine offering real-time scanning and automatic definition updates. As soon as a new file is downloaded, installed, or modified, it should be checked against the latest signatures and heuristics without noticeable lag. Updates to the virus database have to run silently in the background over Wi-Fi or mobile data, with fallback scheduling if the network is unavailable. I’d ...
I need a lightweight Android application that lets two users share one device’s screen in real time with crisp 1080p video and clear, low-latency audio. While the session is live, participants should also be able to exchange text messages in a small chat pane that can be shown or hidden without interrupting the stream. Core requirements • Runs smoothly on current Android versions, handling typical 30 fps desktop-class rendering without stutter • Uses efficient codecs (e.g., H.264 / AAC via WebRTC or a comparable stack) to keep bandwidth below 3 Mbps whenever possible • One-tap “Start session / Join session” workflow—no complicated log-ins or room creation needed • In-session text chat with message history retained only for that session (...
Building an Fintech Mobile First App. We’re looking for a passionate Mobile App Developer Intern or fresher with strong coding, Data Structures, and Algorithms skills to join our team at Instient.ai. Location: Greater Noida, India Company: Skills: Kotlin Multiplatform / Flutter Internship Duration: 3 Months Work Mode: In-Person only (No remote work) If you’re interested, please apply using the form below:
I’m planning a mobile application that will pair job seekers with job offers on both Android and iOS. The core build must include robust user profiles, along with a fast, accurate job-search experience supported by filters such as location, role … In-app messaging is still open for discussion, so I’m interested in hearing how you would implement or improve that layer while keeping the platform secure and scalable. The app will run dual-sided: one workflow for seekers and another for offers, each with its own dashboard and feature set. I value clean UI/UX, solid documentation, and maintainable code (React Native, Flutter, or Swift/Kotlin native—whichever you feel best fits the brief). Please share at least one live link or store listing of a similar app you crea...
I have a RecyclerView driven by a LinearLayoutManager. Card taps are currently picked up through an OnPress handler, and I already keep the underlying data in a ViewModel. The problem is simple: when a user opens a detail screen from any card and then presses the back button, the list always jumps back to the very top instead of revealing the card they originally tapped. I need the list to remember its exact scroll position so that returning feels seamless. You’re free to solve it however you feel is cleanest—saving and restoring the layout manager state, using the Navigation component’s back-stack handling, or any other proven method—as long as: • the previous scroll position is restored every time, • orientation changes don’t break the fi...
I need a skilled Android developer to transform my concept into a fully functional, Play-Store-ready application. The project targets the latest Android releases, so solid knowledge of native Android (Kotlin or Java) is essential. I’m open to modern frameworks such as Flutter if you can guarantee a smooth Android-only build. Scope • Translate my wireframes and user-flow notes into an intuitive UI that runs smoothly across common screen sizes. • Build the complete feature set we finalise together; possibilities may include push notifications, secure user sign-in, or even in-app purchases, so prior experience with Firebase, Google Play Billing, or similar services is valuable. • Integrate any necessary back-end APIs, set up local data caching, and ensure the app remains...
I’m looking for a skilled software developer to create a mobile application for Android devices. The main goal is to turn my concept into a reliable, user-friendly app that meets current Google Play standards. Key objectives: • Translate my idea into clear technical requirements and a development roadmap. • Build the Android application, using Kotlin or Java—or another modern stack you recommend—to ensure smooth performance on recent Android versions. • Implement a clean, intuitive user interface that follows Material Design guidelines. • Connect any necessary APIs or back-end services and handle data storage securely. • Test across multiple screen sizes, fix bugs, and prepare the final APK/AAB for submission to Google Play. Deliverabl...
I’m ready to bring a new social networking experience to both iOS and Android and I need a seasoned mobile developer who can take the concept from blank screen to App Store and Google Play release. The core objective is to create a responsive, stable and scalable app that feels genuinely native on each platform while sharing a single codebase where sensible. Here’s what I’m looking for: • A developer who has already shipped social or community-driven apps and can point to live examples. • Proficiency with Swift or Objective-C on iOS, Kotlin or Java on Android, and a proven cross-platform framework if you prefer to accelerate the build (React Native, Flutter, or similar). • Solid back-end knowledge to stand up user authentication, data storage, push n...
I’m building a stripped-down social networking experience that centres entirely on text messaging. The goal is an Android-only app where users can exchange real-time text messages and spin up group chats without the heavier extras of photo sharing or profile feeds. Here’s what I need from you: • A clean Android Studio project (Java or Kotlin) that compiles out of the box. • Core screens for recent chats, one-to-one threads, and group conversations. • Real-time delivery of text messages, synced across devices even on spotty connections. • The ability for any user to create, name, and invite others to a group chat. • Push notifications for new messages. • Basic message history stored securely in the cloud (Firebase, Supabase, or a compara...
I have a RecyclerView driven by a LinearLayoutManager. Card taps are currently picked up through an OnPress handler, and I already keep the underlying data in a ViewModel. The problem is simple: when a user opens a detail screen from any card and then presses the back button, the list always jumps back to the very top instead of revealing the card they originally tapped. I need the list to remember its exact scroll position so that returning feels seamless. You’re free to solve it however you feel is cleanest—saving and restoring the layout manager state, using the Navigation component’s back-stack handling, or any other proven method—as long as: • the previous scroll position is restored every time, • orientation changes don’t break the fi...
I already have the core screens in place for an Android agri-tech application that will serve three field-side user roles plus one admin panel. What I need now is an experienced Android developer who can take the project from this UI prototype through to a production-ready release on Google Play. Scope of work • Wire the existing layouts to a robust back end so that every user can input data, monitor it in real time and receive analytic dashboards that make sense in the field. • Build an alert and notification flow (push & in-app) to keep farmers instantly informed of anything that demands attention. • Integrate a payment gateway so transactions inside the app run securely and are audit-ready. • Prepare all artefacts required for Google Play publication, gu...
I’m building a new social-networking experience focused on fast, reliable messaging for Android. The scope is a native Android app where users can register, find friends, and chat one-to-one or in groups with text, emojis, and read receipts. Core deliverables • An Android Studio project written in Kotlin (Java is acceptable if you strongly prefer) • Clean, modular architecture (MVVM or similar) with clear documentation • Firebase, Supabase, or another real-time backend wired up for authentication and message sync • Basic material-design UI: login/signup, contact list, chat screen, settings • APK and source code ready for submission to Google Play, plus a brief hand-over guide While the first milestone covers messaging only, I’d like the codeb...
I’m ready to turn my game concept into a polished Android application and need a developer who can take the project from first prototype to Google Play release. The core objective is simple: build a fun, stable, and performance-optimised gaming app exclusively for Android phones and tablets. You will handle the full development cycle—coding, asset integration, basic UI, local data storage, and Google Play Services (achievements, leaderboards, cloud saves). I already have draft gameplay mechanics and artwork; you’ll weave these together, advise on the best engine or native stack (Unity, Godot, Kotlin + OpenGL, etc.), and keep frame rates smooth across common mid-range devices. Deliverables • One signed, installable APK ready for internal testing • Clean, we...
I need a production-ready Android application that lets gamers enter Free Fire and BGMI single-elimination tournaments using a dual-currency system. Players will spend coins to register, earn diamonds for every kill and final position, then redeem those diamonds for Amazon, Flipkart, or Google Play gift cards inside the app. Core experience • Clean, modern UI with separate weekly and monthly leaderboards that reset automatically. • Email-and-password login only; no social or phone auth is required. • Coins and diamonds must be handled by a secure, server-side wallet so no values are stored locally. • Offerwalls (Timewall, CPAlead, Monlix) should credit coins instantly once their callbacks fire. • I will supply my unity account—ads keep the app comp...
I’m moving forward with a fresh Android-only mobile application centred on social networking. The core idea is to let users create profiles, connect with friends, post updates, and interact in real time, but I’m deliberately keeping the feature set flexible so we can iterate together as the concept evolves. Here’s what I need from you: • A solid Android build (Kotlin or Java) that runs smoothly on current OS versions. • Clean, well-documented code pushed regularly to a Git repository. • An early prototype (APK) we can test on physical devices, followed by improvements based on feedback. • Basic backend integration—Firebase, Supabase, or a stack you recommend—for authentication, data storage, and push notifications. I’ll provide wire...
I want to launch a word-puzzle game exclusively for Android that can turn a profit on Google Play. The gameplay revolves around players arranging or guessing words, with a clear difficulty curve spread across multiple, well-balanced levels—the only mandatory feature at this stage. Please build the game in an engine you are comfortable with (Unity, Android Studio with Kotlin/Java, or Flutter are all fine) and include lightweight AdMob integration so the title can start generating revenue from day one. If you see other monetisation tactics that suit a word game, feel free to propose them, but keep the first release lean and focused on rock-solid core mechanics. Deliverables • Release-ready APK • Full source code and project files • Documentation on how to add or ...
Dukandar – Smart Offline Retail Business & Sales Ledger Dukandar is a modern Android-based business management application designed for small retailers, kirana stores, shopkeepers, and MSME businesses to digitally manage their daily sales, cash collections, online/UPI payments, expenses, profits, transaction history, and financial analytics — without depending on an active internet connection. The application follows an offline-first architecture, allowing business data to be stored locally and accessed instantly. It replaces traditional paper-based management with a clean, intuitive and mobile-friendly digital ledger. The app provides a centralized dashboard for monitoring Cash Collection, Online UPI Collection, Total Sales, Expenses and Net Profit, while its analytics...
I want to bring a new social‐networking idea to life on Android. The project starts with a clean slate, so you will be responsible for transforming my concept into a fully functioning app—from setting up the project structure through to a polished release build ready for Google Play. Core expectations • Design and develop the entire Android application in Kotlin or Java, following modern Material 3 guidelines. • Implement the essential social features we will finalise together (user sign-up/login, profile pages, posting, commenting, liking, real-time updates, and push notifications). • Connect the app to a secure, scalable backend of your choice (Firebase, AWS Amplify, custom REST, etc.) and document the API endpoints clearly for future maintenance. • Ens...
I need an Android APK that focuses on one clear flow: letting new or existing customers complete a payday-loan application quickly and securely. Core flow • Users land on an OTP screen, enter their phone number, and receive a one-time code to unlock the app. • After successful verification, they reach a single multi-step form that gathers their personal information (name and address), employment details, and bank information. • When the final step is submitted, the data should be stored safely in a backend or Firebase collection I can later review. Interface & tech notes • A lightweight, modern UI in Kotlin or Flutter is fine—choose whichever you work fastest in. • Keep the code organised so I can hand it to another developer later for interes...
I’m looking for a developer who can turn my idea into a fully functioning Android e-commerce app. The goal is to let users browse products, add them to a cart, and complete checkout smoothly on their phones. Key objectives • Build a clean, intuitive Android interface that loads quickly on mid-range devices. • Implement core e-commerce features: product listing, search and filtering, cart management, secure checkout, and basic order tracking. • Connect the app to a simple, well-documented backend (Firebase, Supabase, or another lightweight stack you’re comfortable with). • Integrate at least one popular payment gateway suitable for my target market. • Provide authentication via email or social accounts and store user data securely. Deliverables...
I want to bring “Good to my life” to the stores as a health-and-fitness mobile app focused purely on workout plans. The goal is a clean, intuitive experience that helps users choose or build routines, schedule them, and track completion without extra distractions. Here’s what I need: • Workout plans – the heart of the app. Users must be able to browse preset routines and create, edit, or duplicate their own plans. A simple calendar view for scheduling sessions and a progress log that checks off completed workouts will cover the first release. Everything else—nutrition or broader activity tracking—can wait; I prefer to keep v1 lightweight, fast, and maintainable. Please target both iOS and Android; the framework is up to you, as long as the UI fee...
I need a skilled Android developer to build a dedicated e-commerce application from the ground up. The core goal is to give users a smooth shopping experience on Android phones and tablets, so performance and intuitive UI patterns matter as much as clean code. Here are the essentials I must see in the first release: • Product catalog that lets shoppers browse, filter, and view detailed item pages • Shopping cart that updates in real time and persists between sessions • Secure payment-gateway integration (I’m open to Stripe, PayPal, or any PCI-compliant option you recommend) Everything should be written natively for Android—Kotlin is my preferred language, though Java is acceptable if it speeds up delivery. I will provide branding assets and product data ...
I’m ready to turn my concept into a polished Android application and need a developer who can take the idea from the first mock-up all the way to the Play Store. The focus is 100 % Android—iOS isn’t in scope for this phase—so deep experience with Android Studio, Kotlin or Java, Material Design, and the common Google Play services is essential. I’ll supply the core feature list and wireframes; you’ll translate them into clean, maintainable code, craft an intuitive UI, and set up analytics, crash reporting, and simple CI/CD. Along the way, please advise on testing, versioning, and publishing so we end up with an AAB/APK that’s fully Play Console-ready. Deliverables • Source code in my Git repository • Release-ready AAB/APK plus signed...
I need a lightweight Android app that can take data about an approaching chicken—distance, speed, or any other sensor input we decide on—and instantly predict the safest time for it to cross a road. The prediction should be shown on-screen in simple, clear language so a farmer or handler can act without hesitation. Core requirement • Predict road-crossing times in real time for a single or multiple chickens. I do not need location tracking or intersection alerts in this phase; the entire focus is on accurate, fast predictions and an intuitive user interface. Preferred approach You are free to work with native Android (Java or Kotlin) or a well-supported cross-platform stack such as Flutter or React Native as long as the final build runs smoothly on current Android v...
I’m building an Android-only mobile app and I need a self-contained AI “command skill” that works purely through typed input. The goal is simple: when a user enters a natural-language request in a text field, the skill should recognise intent, extract any required parameters, and hand the result back to the main app so we can trigger the correct feature or workflow. Here’s what matters most to me: • Accurate intent recognition on common, short queries as well as longer, conversational text. • Fast response times; round-trip latency under a second when using a cloud NLP service, or comparable speed when running locally with a lightweight on-device model. • A clean Android interface (Java or Kotlin—your choice) that exposes one callable fun...
Saya ingin membuat sebuah aplikasi mobile khusus untuk platform Android. Fokus utama tahap awal ini adalah mendapatkan versi dasar yang sudah bisa dijalankan agar ide aplikasi dapat segera diuji. Lingkup kerja yang saya harapkan: • Menyusun arsitektur proyek di Android Studio (Java atau Kotlin). • Mendesain wireframe sederhana untuk alur layar utama. • Membangun prototipe fungsional dengan setidaknya dua layar yang saling terhubung. • Menyiapkan dokumentasi singkat tentang struktur kode dan langkah build + install ke perangkat. Harap lampirkan file source code lengkap, APK debug, dan panduan setup singkat saat pengiriman.
Saya membutuhkan seorang programmer mobile yang dapat membangun aplikasi Android dari awal. Fokus utama saya adalah: • Merancang antarmuka pengguna yang intuitif dan responsif sesuai panduan Material Design. • Membangun fungsi inti (login, database lokal / remote, dan notifikasi push). • Mengintegrasikan API eksternal yang akan saya sediakan. • Menyiapkan build release, file APK, dan dokumentasi ringkas agar mudah dipublikasikan ke Google Play. Kriteria keberhasilan: aplikasi berjalan lancar di perangkat Android versi terbaru, kode bersih dan terstruktur (Kotlin atau Java), serta disertai panduan pemasangan singkat. Bila Anda memiliki portofolio proyek Android serupa, sertakan tautannya agar saya dapat meninjau kualitas kerja Anda. Saya siap berdiskusi menge...
Saya ingin sebuah aplikasi pendidikan khusus untuk perangkat Android. Aplikasi ini harus menghadirkan materi belajar interaktif—misalnya video singkat, kuis pilihan ganda, dan ringkasan teks—agar pengguna dapat memahami topik-topik dasar secara mudah. Ruang lingkup pekerjaan: • Rancang antarmuka Material Design yang sederhana dan responsif. • Bangun fitur utama: daftar modul belajar, pemutar konten (teks + video), kuis dengan penilaian otomatis, serta halaman rekap kemajuan. • Pastikan aplikasi dapat berjalan mulus di Android versi terbaru dan tetap kompatibel hingga Android 8.0. • Sertakan kode sumber lengkap (Kotlin atau Java), panduan build, dan file APK siap rilis ke Google Play. Kriteria penerimaan: aplikasi stabil tanpa crash, navigasi in...
Got a great idea for an app? Need a new way to grow your business? We tell you everything you need to know about building a mobile app in 2020.
Learn how to find and successfully work with a freelance Mobile App Developer for your next project.
Learn how to effectively work with freelance App Usability Analysts and optimize your app's usability. Maximize user engagement and conversion rates.