All of the suggestions revolving around caliper measurements/pinch tests get marked as "Can already be done" and sometimes this link is given to show that it can already be done: https://help.trainerize.com/hc/en-us/articles/360033938972-Measuring-Client-Progress

Unfortunately, this cannot already be done. These are the measurements that that page says the app can track:

Body Fat %
Chest
Tricep
Subscapular
Axilla
Suprailiac
Abdomen
Thigh

The problem is that only the thickness (in inches or I assume, centimeters) of each of these body parts can be tracked, and I guess either you calculate the bodyfat % yourself with the calipers or with a BF%-capable bodyweight scale, or the app estimates the caliper BF% using either just the thickness measurements and/or the BF% you estimates and entered (and of course demographic data like gender and your bodyweight, etc.)

What I would like is the ability to track the actual skinfold measurements in millimeters for the limbs/body areas that I've first measured the thickness of in inches (for example, I'd like to track both the wrap-around thickness of biceps/forearms/thighs/calves/waist in inches, and the skinfold measurements of those areas in millimeters).