How the app needs to work:
1. user downloads app from Google Play or Apple store and launches it,
2. user is asked for a login and password (HTTPS API for verification on our side),
3. after logging in, several elements should be available:
- current IP address visible to Internet,
- remaining time,
- a button "Connect to VPN".
4. After clicking the connect button, an .ovpn configuration file is downloaded in the background and used to connect to one of our OpenVPN servers,
5. after establishing a connection:
- button should turn into "Connected. Click to disconnect." and IP address should update to a new given address,
- all internet connection on the mobile phone should be forced to use the connected VPN,
- active connection details should be placed and stay in notification panel (similar how OpenVPN android app works) - with information about current IP address and "You are connected/You are anonymous" text.
I am a professional android app developer with more than 3 years of experience. I am pretty sure I will be able to help you. Message me so that we can discuss on it.