I have been using this app for two years now. It is a great for showing you an ACCURATE weight change overtime. Even if you skip a day or so you will be able to see your overall weight loss in weeks, months & years. This IS a highly positive visual reinforcement tool for days your body natural fluctuations.
My ONE COMPLAINT is that my old data did not transfer with my new phone. I didnt have to repurchase the app etc. But all of my data for the 18mos prior to my current phone was lost. It is not the end of the world but definitely heartbreaking to loose this motivation.
I still HIGHLY recommend this app
Snb.lee about Happy Scale: Simple Weight Loss Tracker with Daily Moving Average Trend Line, v4.5.1