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TVOP is one of the best free video call/chat apps for Android. TVOP has very good quality when it comes to making VoIP calls. It also easily integrates with any Android phone. Users can have free calls via 2G,3G, 4G, Wi-Fi connection also other Internet to PSTN calls & vice versa along with PSTN To PSTN switch calls.
It basically gives user the ability to make calls over internet using the SIP Voice Over IP. The call features include audio/video both. TVOP also has the traditional sms feature included. With the use of PORTSIP and Twilio, VOIP & PSTN calls are initiated. So now the user can make low cost internet calls with ease. It also includes calls using TVOP credits associated to the account created.