After Skype, the number is of Viber.
Viber Android App is used to Viber-to-Viber free calls, IMs, share photos and videos using Internet. Viber has 200 million users all over the world. Viber also recommends 3G and WiFi Internet connection. You can use Viber on Android, iPone, Blackberry, Windows Phone and other many more devices.
Unlike others, Viber use your phone number as its ID and this app automatically detects which of your contacts is using Viber because it synchronize with your contacts.
Android Viber gives you High quality sound (HD), Groups chat up to 40 contacts, fast text messages, stickers, emoticons, OS integration, Share photos and videos form gallery of the device and totally free, no ads :)
Viber Android App supports English, Korean, Turkish, Dutch, Russian, Chinese, Spanish, Arabic, Hebrew, Japanese, Catalan, German, French, Italian, Portuguese and Brazil.
People are willing to give this app six starts due to it is totally free. Most people like this android app due to its quick, clean and easy feature but they also want its profile more personalize.