Did your doctor tell you to take it easy? Give your bum ticker a rest? I know, I know--not always easy in today's stressed-out world. But Azumio's Instant Heart Rate makes it easy to check your heart rate--just to make sure everything's OK. Place the tip of your index finger on your Android phone's camera, and this app shows your heart rate within a couple of seconds. It displays a real-time chart of your heart beats too. The 99-cent Pro version keeps a history of your heart-rate measurements as well.