App for reading a magazine

Hi, We have a monthly magazine that is seldom more than 24 pages for about 1000 members and would like to design an app for members to subscribe, download and the magazine. Members would have to subscribe and pay a monthly, annual subscription fee to read each of the quarterly edition of the magazine. It is mainly a text based magazine with a few pictures. We would like to make this app available on all platforms, windows, ios, android,,,,,,, OK, We are a society called Alcoholics Anonymous and this project is for our members to read recovery stories in a magazine we publish quarterly. Our General Services Office normally print an circulate the magazine to members at a cost to raise funds. These are posted to members and we are attempting to keep up with the electronic age. The magazine can be emailed to you in an electronic fromat. We need to be able to update the magazine ourselves.