There are so many cool apps coming out in the App Store that there isn’t always time to talk about them. However, this one demanded some attention due to its ingenious idea. Heart Monitor is a heart rate monitor that uses the iPhone’s built-in microphone to detect and measure your heart beat.

This is one of those cases where something so simple is pretty smart. All you have to do is hold your iPhone to your chest or under your jaw with the headphone microphone. The iPhone app then “listens” to your heartbeat and takes a measurement of it. Useful for jogging or exercising at the gym.

This is a great idea for those that have a goal heart rate or wish to keep track of it while on the go. This is also a good thing to have for people with sensitive hearts, who need to keep their heart rate under a certain level when exercising.

It’s stated that it works best with the 3G model of the iPhone and is for sale in the App Store for $4.99.