Way to eating disorder app developer

The measurements on this app make no sense. It says Im overweight 7th percentile but 93% of teens are heavier then me if I use another app or go to the doctor it tells me Im my bmi is 17.0 thats average.

This nickname is taken (sry) about Teen BMI (Find out how your WEIGHT, HEIGHT and BMI compares with others of the same age), v1.1