Build me an academic app

I need an academic app which can be used by different schools and students and can work in all devices (particularly in android Tablets, android Phones and in Laptops using Windows). The app I need will be a platform which teachers of schools can use to create examination questions, games and video lessons for their students. When a user (a student) downloads the app from play store: he will be required to sign up. The app tells the user: Enter your email, any password, to continue. After email and password are submitted, the user may continue to sign up /register or may SKIP registration to enter app immediately. If user skips registration, he can try some features of the app for free for a specified time after which he will be asked to complete registration if he wants to keep on using the app. To complete registration, he enters his email and password and the following 1) Enter School Name 2) Enter School Code (the Schools that will use the App must have been pre-registered and codes generated for them by the General or Super Admin). If a school with a name: St John’s High School had been pre-registered, and the code sent to the Admin in St John High School is correctly entered by the user, the App says: UserName, welcome to St John High School (showing St John Logo and maybe some pictures of St John). The User details which must have been pre-registered by the school admin comes up for the User to confirm and continue. User details will include: Name, Department/Level, Paper/Course/Subject, Exam Code. After proper registration, the user can then have access to the Selection Menu to perform any of the activities of the app. The activities of the app should work offline.