You can use smartvoip on your iphone. Smartvoip call it their MobileVOIP App. With smartvoip MobileVOIP, you can make FREE WIFI calls using your iphone.

Smartvoip iphone app features:

* Make and receive calls from your iphone mobile at very low rates using VOIP
* No change in using your iphone, just select contacts or use redial
* The smartvoip iphone app works all over the world, anywhere, anytime
* Now you’ll be making VOIP calls without using cellular minutes
* You may even be able to downgrade your voice plan
* Quality is very good
* MobileVOIP uses Wifi, 3G, GPRS, EDGE or UMTS – you can select which method when starting the application.

In order to use the smartvoip iphone app, firstly you must register yourself on their smarvoip site. Then there are 3 ways to install the smartvoip iphone app;
1) On their site, you enter your mobile number and then receive a free sms containing the download link.
2) Download the app thru apple iphone app store
3) Download it and install from your desktop

With RingCentral iphone app, you can do your business on the go. You can use the app to:

* Make VoIP calls without using minutes from your wireless plan.
* Place calls with RingOut if Wi-Fi isn’t available.
* Present a professional image by showing your RingCentral main number as your Caller ID.
* Stay connected with instant alerts when you have new messages or missed calls.
* Manage your calls—get the ones you want, avoid the ones you don’t.

The RingCentral iphone app is free with any RingCentral plan.

With rebtel iphone app, you can call fixed and mobile phones all over the world with great voice quality. Using the rebtel iphone app will entitle you to pay only for the time you talk. You do not have to sign any contract and theres no hidden fees. All you need to is to download the rebtel iphone app. Then you pick a contact from your address book and Rebtel gives you a local number to call for a fraction of your international rate. The local number is saved to your address book so that you can use it anytime, anywhere. With the rebtel iphone app, there is no need for WiFi coverage or internet access. Therefore you can reduce the cost of your international calls by up to 90%.

Rebtel iphone app features

* Cheap international calling!
* Manage all your Rebtel numbers
* See available call time for all your buddies
* Check Rebtel rates to other countries
* Check your call and credit history
* Add credit directly from your iPhone

Skype has launched a 3G VoIP application for the iPhone. Skype 2.0 VoIP is now on the iPhone with the capability of making calls over 3G. Initially the users could only use VoIP application over WiFi. With Apple lifting restrictions on iPhone VoIP applications that run over a 3G network, developer agreements were amended by Apple to enable VoIP apps for the iPhone 3G in the Apps Store. VoIP 3G iPhone applications are being offered by VoIP providers such as Fring and iCall.

The company delayed the launching of 3G VoIP applications in order to improve the quality of audio prior to releasing the new version. This application provides high audio quality even with low band-width. This gives an advantage in low band-width situations. One of the new attractive features is the call quality meter or the call quality indicator. It has a grading system consisting of colors. The call quality meter changes colors to red, yellow and green depending on the coverage, with red showing less coverage and green indicating good coverage. Start up time has also been improved in this version and the access has been made easy and fast from iPhone home screen’s dial pad.

As always, folks have great expectations for this new application from Skype. However, Skype will have to work on keeping the prices within affordable limits. They are planning to charge for Skype to Skype calls next year, although the prices will be minimal. Skype is expected to give a good value for its paid products.

Voipbuster has developed a MobileVoip application for the Iphone.
With this new application you can make calls at the same cheap Voipbuster rates you are used to, where ever you are, through Wi-Fi and UMTS/3G.

To start saving on your mobile calls there are three easy ways to get the MobileVoip application;

- Receive a Free SMS with the download link, for this visit http://www.voipbuster.com/en/mobilevoip.php?phonetype=iphone
- Download on your mobile via mobilevoip.com/Iphone and follow the instructions
- Download the application to your PC and install it from your desktop.

Voipstunt has developed a MobileVoip application for the Iphone. With this new application you can make calls at the same cheap Voistunt rates you are used to, where ever you are, through Wi-Fi and UMTS/3G.

To start saving on your mobile calls there are three easy ways to get the MobileVoip application;

- Receive a Free SMS with the download link, for this visit http://voipstunt.com/en/mobilevoip.php?phonetype=iphone
- Download on your mobile via mobilevoip.com/iphone and follow the instructions
- Download the application to your PC and install it from your desktop.