Viber is an iPhone application that lets you make free phone calls and send free text messages to other iPhone users that have Viber installed. When you use Viber, your phone calls to any other Viber user are free, and the sound quality is much better than a regular call.

You can call any Viber user, anywhere in the world, for free and now also text them. All Viber features are 100% FREE and do not require any additional “in application” purchase.

* COMPLETELY FREE AND WITH NO ADS: Viber and all Viber features are absolutely free and do not require any additional “in application” purchase. Once you and your friends install the free Viber application, you can use it to talk and also text as much as you want. Just makes sure all your friends get Viber! All you need is an Internet connection: 3G or Wi-Fi where available. On top of that, Viber doesn’t contain any annoying ads.
* NO INTERNATIONAL CHARGES: It doesn’t matter where you or your friends are, be it on the same network or in a totally different country. You can talk for as much as you want, for free. Just make sure your friends have Viber too.

* NO USERNAMES, PASSWORDS OR REGISTRATION: You know your friend’s phone number, so why bother with yet another username and password? Viber uses your phone number as your “identity” and lets you make free Viber phone calls to any of your friends that have Viber – using THEIR phone number.

* NO NEED TO ADD BUDDIES: Unlike applications like Skype, Windows Live Messenger or Fring where you need to “add buddies” and have them approve you, Viber behaves just like a phone. Just like you do not need to “add” someone in order to call them, you do not need to add your friends in order to call them on Viber. If you know their phone number, then you know their Viber number, and you’re ready to go!
* DON’T KILL YOUR VIBER: To make sure you always get incoming calls/messages notifications, we strongly recommend you to keep Viber running in the background. This does not drain your battery or use up memory and improves your Viber experience.

* SOUND QUALITY: Viber uses state of the art technology in order to make sure the sound quality you get is much better than GSM or a regular phone call.

* IPOD TOUCH and IPAD support is almost here!

* MUCH MORE COMING: We are hard at work bringing many more features to your Viber phone. More ringtones (and custom ones), wallpapers, location based services and more are all coming soon to Viber!

Pros

1. Yes when you are in area with strong internet connection, this application works like magic
2. There’s even messenger included? wow!
3. Very user friendly

Cons

1. When you are using 3G connection at very bad signal location, don’t bother using voice call…try the messenger instead you won’t lose more hair over it.
2. Does other smart phones support viber? …I think Andriod getting a beta version of Viber hence…may improve over time.
3. There’s no video calling where skype & fring is touting their services but obviously video calls can also suffer when using 3G or lower connection.
4. TalkBox & Cloudtalk provided voice recording instead of live call which may be much better alternative when connection speed is bad maybe the developer can “add into” the next update?

Overall, as a free application this app just changed your iPhone or Android (Coming) into a VOIP landlines for free and when you are in strong WIFI connection keep this app running at the background and you will be able to use it just like a land line for your friends to call you FREE of charge.