4. Cardiio ($2.99)
Created by scientists at the Massachusetts Institute of Technology and Harvard, the app uses the phone's camera to measure how fast your heart is beating. It also uses your heart rate to provide insight on your fitness level.
5. Withings Health Companion (free)
This app keeps an eye on your blood pressure while also tracking weight, activity level and sleep patterns. In addition, the company has developed a blood pressure cuff that works with your iPhone.
6. AliveCor ECG Heart Monitor (about $200)
This app records the heart's electrical activity, and when you share this data with your doc, it helps him or her diagnose atrial fibrillation and other heart issues using an ECG case that you hold up to your chest.
Visit the AARP home page every day for great deals and for tips on keeping healthy and sharp