Its a single app.
The app is for general public to get the information and app user can login with specific username and password ( Identification and validation). MySQL Database with PHP 5.0 or above.
1. General Information : about the Group/Individual school , Staff details, Events, online admission, Courses offered and Achievers and Results etc.
2. Academics : syllabus, Subject Notes,Assignments/Projects, Course details, Class Schedules and homework.
3. Attendance and Class Routine modules etc
4. Examinations : Exam schedules, Scores and results etc
5. Library, Fee and Hostel Management .... so on
The major task to work with are
1. Identification/authentication ( google,Facebook) and Firebase messaging/notifications.
2. Fee Management module
3. Assignments/Notes upload and download.
I think now you will have the broader idea.
regards