Sipdroid is an open-source SIP client for Android.
What's New in This Release:
· Fixes lockscreen issue
What's New in 3.0:
· TLS Security
What's New in 2.9:
· Quick fix for Jelly Bean
What's New in 2
MobileVOIP - With MobileVoip you can make free* voip calls from your mobile phone. Make calls to any country you desire at the cheapest rates. MobileVoip is currently supported on iPhones, Android phones and Symbian phones. Simply download the free MobileVoip app from one uour APP market and register with one of the supported Voip brands
Bria for Android Tablets - Bria is a powerful VoIP softphone for Android tablets. It uses a 3G or WiFi connection to make and receive calls.
Bria offers superior audio quality with the included G.711, G.722, GSM, iLBC and SILK codecs
IMSDroid is the first fully featured open source SIP/IMS client for Android. It is also the only free Android SIP client which supports direct Video Calls.
3GPP IMS (IP Multimedia Subsystem) is the next generation network for delivering IP multimedia services. IMS is standardized by the 3rd Generation Partnership Project (3GPP)
Voip One Click is an Android app which allows users to make free encrypted VoIP calls. It uses the TLS protocol to encrypt the information call (caller id /called id), and the SRTP protocol to encrypt the audio communication.
Voip One Click enables users to dial and receive mobile voice calls which cannot be intercepted
Yelo : Cheap Calls Worldwide - Use the Yelo App to make cheap calls to anyone, anywhere in the world on their normal mobile or fixed landline numbers. No more shock phone bills!
Enjoy low rates up to 99% cheaper than your network operator and over 50% cheaper on average than other calling services including SkypeOut, Rebtel or Jajah
Ozeki VoIP Service Checker - Ozeki VoIP Service Checker is an open source app which allows you to check the availability of VoIP services. The software can quickly verify if a given service exists, whether it can be reached from a particular network, and if the username and password to access that service are correct
EasyCallBack for Android - EasyCallBack allows you to make cheap international calls via 3G or WiFi from your mobile phone. Simply download the app, create an account, add some credit and start enjoying low-cost calls.
Calling someone is very easy. Start by entering the number you wish to dial. EasyCallBack will call you back and then will connect you to your destination