One of the common ways to track your weight when doing it manually is to average out the weight over all the days of the week to counteract the weight fluctuations that occur on a day to day basis.

Being able to see this in the app would make it much easier to see if the weight is moving in the desired direction.
Right now it can be a little confusing if the "one month ago" weight happens to have been on a low or high day with the fluctuations.