I made a beta version of a calorie-tracking app. The funny thing is, I built it backwards. I initially made it for myself. A friend started using it and really liked it, which made me think about turning it into something bigger. But now I'm questioning the whole thing. There are already hundreds of calorie-tracking apps, and I don't think I have a strong USP yet. I don't want to solve the problem of “I need another calorie tracker.” I'd rather find a real problem that people who ...