Wikipedia
FriendCaller is a Video and Voice over Internet protocol developed by C2Call GmbH based in Werl, Germany. Its proprietary Voice-Over-Internet technology was originally created by Michael Knecht and Martin Feuerhahn. It was a first prototype developed by Actai Networks GmbH in 2007; the technology was then transferred to C2Call GmbH in 2008. Later on, FriendCaller was launched in 2009 as a website and as an iOS ( iPhone, iPad, iPod touch) app. FriendCaller establishes peer-to-peer connectivity and allow users to communicate one-to-one or in groups via Video Chat, Voice over IP, Instant messaging, Texts/SMS, and phone calls.
Calls to other FriendCaller users within FriendCaller are free of charge, while calls and SMS to phone numbers and mobile numbers within the PSTN network are charged via debit-based user account system. FriendCaller also became popular for its advanced mobile features like multi-point video conferencing with up to 7 participants who are displayed simultaneously in one live stream. Unlike most VoIP service, FriendCaller operates in any desktop browser without prerequisite software installation and works across Multi Operating System Platforms. The browser-based capabilities are Java-based and do not require Adobe Flash and is hosted completely on Amazon's cloud.
Currently, FriendCaller has over 11 Million registered users as of September 2013.