The idea behind Truphone is that when you don't have an affordable cell phone signal, you can use broadband VoIP on your iPhone (or other compatible mobile phone) to make phone calls.

Downloading Truphone on the iPhone is simple. Go to the Apps store and search for Truphone--load the app as usual. When you click on application the first time, it runs you through setting up your phone which is as simple as entering your phone number into the phone and clicking "Go". Truphone calls you and asks you to enter code that you pre selected. After you have crossed that bridge, the phone sends you an SMS message with a username and password for the Truphone site. You do your final setup on the site and they credit you $4.00 to start with. An email validation is sent to your email account.