4 Free Apps That Improve Your Health

Is it okay to exercise outside?

Download: EPA's AIRNow

Get the daily air quality index (ranging from 0 to 500, though it's rare to see levels above 200) in your area by entering your zip code. Having this info on hand should help you take precautions that will let you breathe a little easier.

Next: Dr. Oz: "5 health risks I won't take—and neither should you"