Car makers and accessory companies have been all over promoting their brands via the iPhone, and some--particularly the aftermarket makers--have even found ways to enhance the driving experience, like Viper's SmartStart remote start app. Others, like the new BMW M Power Meter application, take a more indirect approach.

Leveraging the iPhone's built-in accelerometer functions, the BMW M Power Meter Application can measure speed, forward and lateral acceleration, speed over distance, and acceleration to a specific speed, like, for instance, 60 mph. This makes the M Power app fairly full-featured for a performance driving app, though it does come up a bit short of commercial apps like Dynolicious, TrackDay, and gMeter.

Considering it's free and it generates a readout based solely on the iPhone's relative motion, it's a win-win for BMW drivers and enthusiasts of all brands: there's no need to actually own a BMW to use it. Of course, you do have to put up with the blue-and-white Bavarian logo, if that's an issue.

It's also rife with the legal-requisite safety warnings, but with the pretty graphics and the ability to use both metric and standard units, it's actually a useful app, and the price is certainly right. If you really get into it, you can even skin the app, though you'll have to register at BMW's M Power Meter site to get the key to unlock them.

Learn more about the M Power App at the official site below.