Skype
Skype is undoubtedly the most popular VoIP app of all. If you use Skype at home then it should definitely be on your iPhone or iPod touch. To make calls, simply select someone on your Skype contacts list and you’ll be talking in no time.
On top of voice calls, Skype for the iPhone also allows for chats just like the desktop app (it now allows for landscape chat mode). It also permits the user to set his or her status and profile information.
Skype also offers a range of subscriptions that make international calls remarkably inexpensive. You can either pay $5.95 per month to call unlimited landlines in one country of your choice, or $12.95 for any country in the world. A huge money saver if you would otherwise be paying network rates.
Truphone
Truphone is similar to Fring in that it integrates with other accounts you may have such as Twitter, but this is about it. Truephone, just like all of these VoIP apps, has its own contacts list from which you can freely call other Truephone users.
