Better Weigh, an app to help track your weight. Implements the method I used to track my weight while going from 290 lbs. down to 175 lbs.
I find that weighing every day gives the best picture of what you’re weight is actually doing. The problem is that daily diet, exercise variations, and other activities cause your weight to vary by up to several pounds per day. This means you can do everything right on Tuesday, but see your weight go up on Wednesday for reasons that may not be clear. It makes the real changes in time of your weight harder to track. Better Weigh averages your weight measurements over time to show you how your weight is really changing and helping you reach your goal. Currently available for iPhone running iOS 7.1 or later.