I love Loseit... I have been using it for the past 6 weeks and am down 16 lbs. There is a whole forum of people that use it and give feed back and what not (though i havent really used that part). But how it works. Basically its like these other apps and is a calorie counter. It has lots of store bought and restaurant specific foods (a lot of chains, fast foods, ect.) and the calories within them, and lots of excercises and the the calories/hour on 5 min intervals burnt doing them. You set a goal weight and it gives you a time frame and how many calories you can net for each day. It adds the calories you intake and subtracts the calories you output by activities. It shows where you end up for each day week or month.
I coach HS wrestling and generally after the season I take time off from working out and in the process gain about 20 lbs then try and lose it for the summer. The only true way of maintaining and or losing weight is by managing calories, especially as you reach adulthood and your metabolism begins to slow down. People try all sorts of crazy diets and gimmicks to lose weight and find they put it back on quickly once the gimmick ends. If you are worried about your weight or would like to lose a few pounds count your calories see how many you consume without dieting for a week or two. Then try and reduce that by about 500 a day and you will see the difference after a couple weeks. If you you reduce the average by 500 a day that is 1 lbs a week. If you want to lose more per week cut your net daily calories by 1000. For every 3500 calories you subtract from your weekly total your body loses a pound. Thats why this app is great, keep up with it each day and record your info and you will see the weight loss will come. I am someone who greatly enjoys eating so to balance my net calories I add workouts in to keep me below my allotted amount for the day.
A couple quick notes, you should never let your food intake be much less 1000 calories a day for an extended period of time (a few days at most) or let your net be under 500. Your body needs those calories to function and perform daily activities.