Livestrong have produced a combination of apps designed to help you lose weight. The main ones I have used is my plate which helps you, via either the app or the website depending on where you happen to be eating, track your calories, and the excercise tracker. It's the combination of access points which I found most helpful, web & mobile.
Gym Training by Weightplan.com http://tinyurl.com/weightplanapp is an exercise database and exercise routine planner. Weightplan puts over 600 HD exercise photos and videos at your fingertips. With 30 preset gym routines for you to follow you’ll quickly improve strength, tone and muscle mass. Weightplan makes it easy to plan your exercise and track your fitness progress. Watch fully qualified Personal Trainers guide you... more »