Show HN: My first iOS app using RubyMotion

Gems I used: Bubble-Wrap and Formotion

My hypothesis is that you'd do $50 over the first three days and then less than that each month thereafter (unless you have some sort of marketing, but how would you market an app like this?)

This isn't criticism, it's curiousity. I don't think you've done anything wrong, it's a perfectly decent app and serves a clear need. (Though I'd put icons in the tab bar if you could, even just images of the text BMI, etc, would look better.)