As the name suggests, this application lets you send and receive an unlimited number of text messages within the U.S. When you open the app, you're asked to select a username that will appear to your recipients when you send your messages, so be sure to select a name that will be easily recognizable to your friends. TextFree does not use your phone number. Instead, recipients see a ten-digit number and your username within the message.
Because the application resembles the native SMS app for the iPhone, composing messages, selecting recipients, and reading texts will feel familiar. The app prompts you to turn on push notifications for incoming messages. The big difference between TextFree Unlimited and the iPhone's native SMS app is that TextFree does not send or receive multimedia messages, so pictures and videos are out.
When you receive a message while your phone is on standby, it will vibrate and show the incoming notification. Upon unlocking your phone, TextFree takes you straight to the message, just like the native SMS app would. You can also view the inbox, where messages are threaded. One nice perk is the ability to set different themes for the app and individual contacts. You can change tones as you like, and add a signature to your messages, though it eats into the 160-character SMS limit. Overall, TextFree Unlimited is a strong choice for iPhone owners.
Want to read about more apps that dash your text messaging costs? Check out Text Message for Free: Apps for Android, BlackBerry, and iPhone OS.