I have been using this app for about three years now. My Fitness Pal is an app that helps you keep track of what you eat, your fitness, your progress, calorie intake, as well as your daily nutritional break down. You can use the app to set a goal, plus you can have friends which means encouragement. Its not just a phone app, there is also a website for MyFitnessPal, which has even more benefits. Check it out!