How to Make Free Phone Calls on the Internet Through an iPhone

VoIP
1. Launch the App Store application on the iPhone and search for a suitable VoIP app such as Skype, Fring, Tango or Truphone. Tap the app's entry on the search list and press the 'Install' button to download and install the application. If you have an existing account with a specific VoIP service, its iPhone app will allow you to continue using that account on the handset. It's also advisable to check with friends and family as to which network they make use of, so you can connect with them more easily.
2. Launch the VoIP application and create a user account if you don't already have one. Follow the app's on-screen instructions for creating a new account on its network. You will need a unique username, which replaces traditional phone numbers within VoIP networks, and a password. Some apps also require you to enter a working email address for account verification.
3. Sign into your account on the VoIP application by entering your username and password. Locate the details of the person you want to call by selecting them from your contacts list within the application or by entering their username into the application's dialer function.
4. Tap the recipient's entry on the contacts list, or press the 'Call' button after entering a username into the app's dialer function. When the call connects, use the iPhone as if it were a normal phone call. If making a video call, hold the handset in front of you so the camera has a good view of your face.
Google Voice
5. Open the App Store on the iPhone and search for 'Google Voice.' Download the free application and launch it.
6. Tap the 'Sign In' button and enter the username and password for your Google Voice account. If you don't have an account, visit the 'http://google.com/voice' website, select a unique username and password, and click the 'Sign Up' button.
7. Dial the recipient's phone number into the Google Voice app's keypad and press the 'Call' button. The app will dial a Google Voice outgoing number, and then connect you to the recipient's number for free.