a way to track one's symptoms more specifically, especially symptoms related to side effects of medication.
You could simply offer a tracker (maybe inside the settings for the related medication) in which users can record, what side effects they suffer from and how their symptoms have developed. For example: "Did you get a headache today?" and maybe a scale from 1 to 10 or something similar. It would be a big help for me to have all of my medication-stuff in one single app :)