Add a subscription to my iOS App

I have an iOS photo app. It's main function is for taking/editing photos. I would like to monetize the app with a subscription. The requirements are: - 2 week free trial. - monthly charge. - Opens screen when user first opens app that tells that about app(I will send), then when they click button it initiates subscription. - When user has active subscription, this screen does not pop up. -Restore purchases button on the screen. -Check every so often for subscription and if it isn't active, put them back on the initial screen. -If user doesn't start subscription, they cannot access app at all. -You(seller) assign all legal rights/copyright to the work you make to me(the buyer) with no limitation and revoke your rights to go after it.