Cross-platform VOIP mobile app

I need a PoC for a cross-platform VOIP app, with the following features:

1. Allows users to login using their LinkedIn or there Google accounts

2. Allows a logged-in user to see all other logged-in users

3. Allows users to establish a VOIP call with any other online user

Technical details:

1. Should work on both Android and iPhone

2. A server-less solution is OK (no need to spend time on writing server side code), but I need to know in advance the monthly fees I'll have to pay to run the solution

3. Usage of 3rd party VOIP providers is OK, but again I need to know the costs in advance

4. Clean/clear code is very important... Also I'll need a documentation on how to build and run the code is my environment

Please bare in mind when bidding that this project is mainly about finding good existing APIs, and integrating them in a cross-platform application, so it's really simple if you know what you're doing

Android iPhone Java Desarrollo de apps móviles VoIP

Nº del proyecto: #15658611

Sobre el proyecto