Viber

This is a VoIP (Internet telephony) app for smartphones, working on Android, BlackBerry OS, iOS, Symbian, Windows Phone, Bada, and for PCs which operate on Windows, OS X and Lunix (officially only Ubuntu 64 bit and Fedora 64 bit have been tested in combination with Viber). It allows users to make free calls between smartphones with Viber installed through Wi-Fi and 3G (you pay only for the Internet traffic). You can also send text messages, images, video and audio messages through it.

Initialy, Viber was launched on iPhone back in December 2010. A preliminary Android version came out in May 2011, but access to it was limited to 50,000 users. The final version was released on July 19, 2012. Viber for BlackBerry, Bada, and Windows Phone came out on May 8, 2012. On 7 May 2013 the iOS version was updated to version 3.0, along with its release the new desktop Viber versions for Windows and OS X were announced.

On January 14, 2014, the Japanese electronic commerce and Internet company stated its intention to purchase Viber for $900 mn. The deal was closed in February 2014.

Total user base: over 500 mn.

Founder: Talmon Marco and Igor Magazinik.

Current owner: Rakuten, Inc. belonging to the Japanese billionaire Hiroshi Mikitani.

Company value: $900 mn as of February 2014.