When we first covered SmartFuel from Nasvhille-based Iridium Development, not only did the app impress with GPS routing from Navteq, but also the app’s partnerships with OPIS and Wright Express, providing  over 1 million price updates daily from over 130,000 gas stations.

In short, SmartFuel is a free iPhone app providing frighteningly (in a good way) accurate gas prices at stations in your area by  accessing the world’s leading fuel price database.  By adding the type of fuel your vehicle uses, when one searches for nearby stations, SmartFuel automatically calculates how much you’ll save on gasoline.

If SmartFuel stopped there it would remain an invaluable resource for commuters or those traveling by motorized vehicle, but with version 1.1 now available, SmartFuel has become even more of a must-have app.

Version 1.1 offers a completely redesigned UI, station safety and cleanliness ratings, and social network integration.

SmartFuel now allows users to share savings on gas through Facebook and/or Twitter and will even automatically share savings milestones of ($50, $100, $200) if one elects to do so.

A search for gas stations using SmartFuel displays the most up-to-date savings at stations along your route, gas prices nearby or up to 100 miles ahead of you, and has the ability to sort by lowest price, closest station or most recently updated price, providing exact, in-app driving directions to your chosen station.

Moreover, the app shows user-generated station ratings on safety and cleanliness, allows you to rate the stations you visit, store commonly visited destinations, tracks your savings per fill-up and shows you accumulated savings over time.

SmartFuel, while a free app to download, offers its real-time pricing service free for the first 30 days.  Following the introductory period, one can continue getting updated price information through an in-app subscription ($4.99 for six months, $8.99 for twelve months, or $14.99 for twenty-four months, a 25% discount) billed to your iTunes Account.

The app’s new design, social network integration and superb features make SmartFuel an app you’ll want to speedily download.  Further, with the savings you’ll see during the 30-day free period, you’ll certainly want to sign up for SmartFuel’s service.  Depending on your vehicle, you’ll make up the cost in only 1-2 fill-ups!

Download SmartFuel from iTunes here.