1:50 PM -- If you were at this month's Boston Marathon and you saw a life-sized iPhone run by, trailed closely by a giant Android, you've seen the men behind RunKeeper. If you are a runner yourself, you'll know why they're awesome (as if running 26.2 miles in full costume wasn't enough).

The details: RunKeeper is a free GPS-enabled fitness app available on both the iPhone and, as of last week, Android. When fired up, the app tracks how far a walker, runner, hiker, or biker has traveled, including average speed, distance, calories burned, and route. The proud athlete can also tie the app into Twitter or Facebook to let others know her progress and location. The $9.99 Pro version of the app lets users generate reports based on their training, analyzes runs, and enables audio cues (like "Run faster!"). Why it stands out: On the iPhone, the app is limited by AT&T Inc. (NYSE: T)'s often-shoddy network coverage and the iPhone's own limitations, like a lack of multitasking (no taking calls while using RunKeeper, but hey, you're running). Otherwise it's a great tool. The information it provides can augment a run for those training for a race or provide enough context to make it fun for non-runners to leave the couch. It's often compared to Apple's $29 Nike/iPod combo, but the price point, its inclusion of live maps, and the fact that it requires no new hardware makes it an ideal running companion.

RunKeeper’s take: While training for his first marathon in 2007, founder and CEO Jason Jacobs realized the need for more information while on the go, and the iPhone emerged around the same time as the perfect means to deliver that info. Turns out more than a million mobile phone owners agreed. Jacobs said growth and continued improvements are his main goal now.

"Our big vision is, as the smartphone market matures, any carrier or device or platform that emerges as a contender, we want to be there and be the leader," Jacobs says.

[Ed. Note: In case you were wondering, the iPhone beat Android at the Boston Marathon, but it was Android's first time... and he was barefoot. Story of his life.]

— Sarah Reedy, Senior Reporter, Light Reading Mobile