Linphone is an open source app offering free audio/video calls and text messaging. With Linphone, you can be reachable at any time, even if the app is closed, with a WiFi or 3G/4G internet connection. Linphone key features: * high definition audio and video calls * audio conference calls with various participants * pictures and file sharing * Linphone accounts reachable at any time, even if the app is closed (thanks to push notifications) * secure communication (encryption options) * compliant