I felt compelled to write this because I love using this app so much. It works so well for tracking and averaging weight loss so you can send trends over time, and its super reliable and easy to use. All the functionality is there if you use the free version, but I upgraded because I just like it so much I wanted to support the developer.
crystalkitten about Happy Scale: Simple Weight Loss Tracker with Daily Moving Average Trend Line, v4.5.1