Main features: Free calls to US and Canadian numbers. Free calls to more than 2000 VoIP networks. For instructions please visit https://www.sipmobile.org/wiki/wiki/how-to-call/ Audio/video calls. Online and offline messages. Push notifications for longer battery life. Secure communications with cryptographic software. Supports modern codecs (Opus, WP8) for better audio/video quality. Picture sharing. Compatible with Sipmobile soft phone for iOS and Windows Phone. Inside Sipmobile domain you can use Self-Administration service. This service allows you: view recent calls. use click-to-dial service.manage voicemail (Voice mail number is 2000).maintain your address book.set call barring for incoming and outgoing calls.set your personal alarms.manage your account password.