An iOS8+/HealthKit app for quick entry of weight into HealthKit, as well as a learning iOS development project.
The app retrieves your last recorded weight from the HealthKit store, and allows you to make a quick entry of a new weight with a slider, rather than inputting it through the Apple Health app.
It will not allow you to enter a new weight more than once every 10 minutes, and it needs that at least one data point is already present in HealthKit.