We need to develop:
1. A Web application backend in php/mysql for managing the below applications which you will also create:
2. A Native Android tablet application (needs to be integrated with SIP server)
3. A Voip app for Android and IPhone similar to Rebtel/viber in functions
(needs to be integrated with SIP server)
Both 2 and 3 must be integrated together with web application backend and sip server. You must have experience with xmpp,sip,asterix,freeswitch and similar technologies.