Back in February, we blogged about Viber, a popular VoIP app that allowed iPhone users to enjoy free VoIP calls to fellow Viber users through WiFi and 3G. At the time, Viber was only exclusive to the iPhone, but they finally released an app for Android devices today. There are a bunch of features unique to Android, including pop-up text message notifications, full call screens, and integration with your phone’s messaging and call logs. You can even set your Viber number as your default dialer. The Viber Android app is still in beta mode though, but you can start downloading it here.

Fring just one-upped their biggest competitor Skype by offering a new Video calling feature for Android and iOS users. Users who have the app can initiate video conferences over WiFi or 3G that accepts up to four participants. However, it’s not quite available to the public just yet. The video call feature is part of Fring Beta, and you can only get the app if you request it. The iPhone Beta request is over, but Android users can still ask for their Beta invite here. Enjoy!

The mobile VoIP market has an infinite number of choices, with so many start-ups competing for the patronage of mobile users. You’re probably familiar with the major players – Skype, GTalk, Nimbizz, and Tru, to name a few. Morodo is a company you probably might not heard of, but they just gave their Android app a brand new user interface and a VoIP feature, allowing you to make voice calls while minimizing your costs. MO-Call is free on the Android Market, and is also available in other platforms like iOS, BlackBerry, Windows Mobile, and Java. Download the MO-Call Android app here.

This week, Nimbuzz launched their social networking and VoIP app in the Android marketplace, with brand new features for Android users. Exclusive features to the Android include support for Skype, a new buddy list layout, a time-sensitive user interface, auto-reconnect, and local social network support, making it the most sophisticated social messaging app for the Android. The

The new buddy list layout displays the avatar and presence information at the same time, as well as resource information (e.g. lets you know if your buddy is on the PC or mobile).

The time-sensitive user interface detects how long you hit a buddy’s name. With a light touch, you can open your profile, but a strong tap starts a new text conversation.

Home screen notifications let you know activities like incoming chats while Nimbuzz runs on the background.

Clickable URLs let you share YouTube videos, websites, and other links through the chat window. Simply click on the URL and a browser window will open, and you can simply switch back and forth to Nimbuzz.

Finally, the auto-reconnect feature. When Nimbuzz detects that you’re out of range from a WiFi network and there isn’t a WiFi hotspot nearby, it connects you to 3G and vice versa.

The Nimbuzz app is now available on the Android Marketplace.