If you haven't already downloaded the Amazon Appstore to your Android phone, be sure to do so. Then check there daily for a new free (premium) app. These are apps that usually have a cost, but for that day only they are free.
Today's free app is a great one if you are wanting to lose weight, or just track your weight/ exercise or calories.
Cardio Trainer Pro is an awelsome little app with several free plugins to help you track your workouts. It even acts as a pedometer to help you track your walks/runs whether on a treadmill, on a track, or just outside on the road or on trails. When you download the original free app (which you will be prompted to do), you'll find that it sets up daily reminders for your workouts, encouraging you to keep on your plan. Then be sure to add Calorific to track calorie intake and set those goals. I started using this app as soon as I downloaded it and already used it to monitor my treadmill walk. The accuracy is not perfect (as far as your speed and end time), but the end result was pretty much spot on. This is one app I'm happy I came across and even if it wasn't free, it would be worth paying for.