Native Android App Development for e-Learning

Hello. I need an android application built. It would be a very basic mobile app with a web backend for the admin and teachers, with the following features for the 3 types of users: Admin (Web): 1. Should be able to add/delete/modify your students and teachers. 2. Should be able to create courses and add/delete/modify material to the same. 3. Adding content can be in three ways: a) Upload a document b) Create a document through the online editor and add anything to it 4. Should be able to create online tests. It may or may not be time-based and can be given only once or multiple times. 5. Message any student or reply to doubts Teacher (Web): Same as admin, except the first point. Student (Mobile): 1. View course material online, without being able to copy or download the same. 2. Take online tests. 3. Contact the admin (or teachers) for doubts. ------ Security Features: Since app purchases will happen online, admin should have the option of generating a unique activation code, which will be required to activate the product first time after download. Responsiveness: The app will be viewable by students on all types of android devices. Make sure it looks good on all.