We've got the beat.

Music player, YouTube surfer, telephone, and… medical doctor? While it’s a touch more Dr. Nick than Doogie Houser, this simple heart-rate measuring app earns at least an honorary nursing degree. Heart Monitor calculates your beats-per-minute and little else. But the process works so well, we can overlook its narrow approach.

A built-in tutorial concisely explains how to automatically measure your heart rate. Just stick the headphone mic on your neck, wrist, heart, or other source of strong blood flow. It listens to your heart, automatically displaying and saving the rate. You can even use the built-in microphone (only on 3G iPhones), but our results were less accurate. Alternatively, you can start the timer mode to manually count the beats yourself. After several seconds, the app asks for your number then calculates the approximate beats-per-minute. Both modes quickly and accurately give results.

Unfortunately, during workouts, we jostled the phone too much to get good automatic readings. We also wanted to annotate--or even save--the list of measurements off the phone. Finally, we wanted a mode to tap out our current heart rhythm and let the app display the average beats-per-minute.