For the most part, useful iPhone apps are pretty hard to come by, especially when you consider that most of the ones that have been released are more of the entertainment variety.

But every so often, a useful app becomes available and those that are privy to its release usually don't hesitate on downloading it. As for those looking to purchase a new - or used - car, that 'useful' app has finally arrived thanks to Kelley Blue Book.

The new app allows the user to link directly to the KBB database where he/she can download any and all relevant information on any car that is part of the KBB database.

On the other end of the see-saw, car owners interested in selling their rides can also make good use of the KBB Seller's Toolkit, which pretty much presents everything you need to know on how to unload your car to folks interested in buying it.

It takes a little getting used to, but once you get the hang of it, the new KBB app becomes useful to anyone with so much as a passing question on what kind of car to buy in the foreseeable future.

.