Develop and integrate Soft phone (SIP, VOIP ) for mutliple platforms

We are looking to develop a softphone like Zoiper, ([login to view URL]) or Zangi ([login to view URL]) some of the features are listed below. Please apply if you have understanding of the project. Access to the native contact list; - Favorites / Speed Dial; - Call History / Contact management; - Voicemail integration / notification (SIP MWI); - Hold / Resume / Redial; - In call contact picture; - Configurable DTMF (SIP INFO / RFCs 2833/4733 / RTP Inband); - Notification Center Support for missed calls, voicemail and registration status; - Blocked Numbers List. • Codecs: - Included: G.711 (uLaw & ALaw), iLBC; - Purchasable: G.722 (Wideband), iSAC (HD), G.729 Annex-B; - Support for UDP and TCP. • Other: - Call Waiting / 2nd Call / Call Toggle / Call Transfer / Conference; - Switch between Multiple SIP accounts (one registration at a time); - Secured SIP Transport (TLS); - Secured Encrypted Media (SRTP) with SDES; - Languages: English, French, German, Spanish, Portuguese, Arabic, Japanese, Chinese (Simplified), Russian, Turkish