Although iphone officially was not made for voip phone but voip service can be used via iphone. All you need is to install a software/application for the iphone. Different voip providers recommend/provide different voip applications for iphone.
Furthermore, companies like Axvoice Inc. recommend wi-fi technology for their voip service if you plan to use it on your iphone. To cut the story short, if you are planning to use voip phone service on iphone, you had better consult your voip provider first.
I am recommending five applications that you should discuss with your voip provider before you start using voip service on your iphone.
This prestigious application with unique iphone features like video calls and unlimited calls is not provided by apple when you purchase your iphone. You need to install it from internet. Like all other applications, it also follows voip protocols. You can use it like MSN messenger or Gtalk. This newly built voip applications can work with iphone as well as android.
This is amongst those applications that is provided by apple to work on iphone platform. This application can convert the digital signals of voip in to signals that are understandable for your iphone. Icall can work with any wifi network.
This is perhaps the most popular soft phone. It is already used on computers for video calls. Good news for skype users is that you can install it on your iphone also and use it as you use on your computer. This application is compatible with wifi, 3G and GPRS networks. You can communicate with other skype users free. If you want to use the voip service for your business, then ultimately skype remains the best option for you. Remember skype is a voip service provider also that offers a dialing service like other phone service providers.
You can decrease your phone bill to 40% while using the vopium voip service. Yes vopium is not only a soft phone but also a voip service provider. This softphone allows 30 minutes of free voip calls. It offers sms service also.
Truphone is another popular softphone. You have to install it on your iphone. Like other soft phones it allows you to communicate with others who are using softphones like skype and iCall. You can call other phone numbers also. Another good offer by truphone is that of free calls to other truphone users. Truphone is a voip provider also.