Yesterday we thought the first iPhone GPS turn-by-turn app to become available would be the MobileNavigator from Navigon.

Today, AT&T released its Navigator app, becoming the first full featured voice-prompted turn-by-turn GPS navigation app to become available on the new iPhone in North America.

The AT&T Navigator app offers voice-guided turn-by-turn notifications, 3D maps, automatic rerouting, POIs, local search, current speed, estimated time to arrival, search for lowest gas prices, search results also tell you how far they currently are, among other features.

The app is a free download, but requires a constant monthly fee of $9.95. The subscription also includes app and new map updates.

The app is now available on iTunes.

AT&T Navigator is built by Sunnyvalue, California-based TeleNav.

The AT&T Navigator seems like a good alternative, and a good option for anyone looking for a GPS solution who wants to use the service for say one month and only pay that small amount.

One of the biggest drawbacks of AT&T Navigator, compared to the other GPS iPhone apps such as the one from Navigon and the upcoming one from TomTom, is that the apps are downloaded in real-time on the AT&T app, meaning if you don’t have cellular coverage in an area, it simply won’t work. So, maybe the other higher priced GPS apps are more worth while, and even more cost-effective in the longer run.

It remains to be seen when TomTom will release their confirmed iPhone app.