You have your iPhone or Android device with you while you trot away on the treadmill or throw around some iron. Why not use that smartphone to help you burn calories, stay fit and stay motivated?

Run Keeper (iOSAndroid)

Track your active fitness progress with this free app available for iOS devices or Android phones.This app uses your phone’s GPS capabilities to map your progress, measure your time and monitor your progress over time.

The name has ‘run’ in it, but this app can track so many more activities, including: cycling, walking, cross-country skiing, downhill skiing, snowboarding, rowing, hiking…the list goes on.

Run Keeper can also control your tunes to keep you motivated while exercising. The coaching option activates voice commands to keep you on pace – and on track to staying fit!

TargetWeight (iOS) BMI Calculator (Android)

Where is your body at? And where do you need to go?

Sure, 180 lbs for a guy measuring six feet high might be a reasonable weight, but what really matters is the Body Mass Index (BMI). This figure tells you more aboutyour figure. Is your weight healthy for someone your height? Or do you need to lower that stat and hit the gym?

TargetWeight will tell you whether your BMI reading categorizes you as being at a healthy weight, overweight or obese. Drag the slider up or down and it will tell you how much weight you need to shed to become healthy.

BMI Calculator for Android is similar, but it doesn’t offer the same ability to set goals.

Instant Heart Rate (iOS,Android)

It’s great that you’re working hard at staying fit, but you need to track your body’s vital signs. You could buy a separate heart rate monitor, but that’s just something extra to carry around at the gym. Instant Heart Rate uses your phone’s camera to read your heart rate. Simply place your finger on the lens and after a few seconds – it will calculate the speed at which your body’s most important organ is beating at.

This app is also useful because it tells you how healthy (or unhealthy) your heart rate is. Too high – need to work on improving your cardio. Below average? You’re doing great. Upgrade to the pro version and track your heart rate readings over time to tell you if you’re heading in the right direction.

If you’re hitting the gym regularly, you probably are.