I love yours as well. I drink an embarrassing amount currently. 2-3 coffee drinks and 4-5 sodas throughout the day.
I'm terrified that if I cut anything, my productiveness will suffer. I didn't even realize how much these drinks were overlapping before seeing these trackers, which is a good first step.
The number 1 thing I would like would be some type text message question I received every couple hours throughout the day. The question would just ask how sleepy I am. I would respond with a 1-5 based on how awake I am.
Then my alert fullness could be charted along with the caffeine in my body to see if they are even matching up. The app could then suggest which drink I could cut out, and suffer the least.