Diet and Exercise

I have reached my limit. I feel so heavy and overweight. I have never felt this way before. Right on time that hubby bought me a new HTC Sensation android phone I got an app that would track my food intake and how much exercise I am getting. This is called a noom app. I think this is cool. So far I have ran 21.8 miles in 14 workouts and that is 3 708 calories taken off. I felt better each time a certain amount of calorie is taken off of me. I am also starting to be conscious with food I eat since it's not easy losing calories. I just hope this would really work. So what works for you when it comes to diet and exercise?