Weirdly a few years ago (7?) I made the most stupid app for a friend. The app was really bad and coded with my feet as I never did a mobile app. It was based on Ionic and just had one screen. It was a feeding calculator for horses for a brand of horse feeds. You input the weight of the animal, the age and it's level of activity and it calculated how much feed to give daily and what type of feed. The app was clunky, outright bad. It got approved on the first try. I was surprised.