I this not just knowing your market? I had a friend drop $20,000 on a new supplement and training business, built out an app for trainers the way he saw though

I this not just knowing your market? I had a friend drop $20,000 on a new supplement and training business, built out an app for trainers the way he saw thought it should be, and recruited trainers. Lots. Showed them the app, and got a lot of feedback, but by then it was too late. He was out of money and no dev wanted a piece of the pie. He should have done his market research first. The OP too, no?