All the time, I hear people with ideas and developers with apps where their plan is to put it in the store and hope it takes off. At best their plan includes ma

All the time, I hear people with ideas and developers with apps where their plan is to put it in the store and hope it takes off. At best their plan includes making a video that goes viral, but they've never done that. If you're targeting a big niche with lots of competition (puzzle games, todo lists, etc.) you must have some sort of compelling hook to stand out. A great endorsement / review lined up, an innovative UI, something controversial, etc. If you're targeting a small niche (bassoonists, bingo card enthusiasts, etc.) you really should test that niche before investing a lot of time into building a product for it. Build the minimum app that can provide value and see how it sells. It's impossible to tell conversion rates for app store searches, but if your 99 cent app with 20 bingo card designs doesn't sell at least a couple a week, that niche isn't looking good. If it sells 100 copies a week, I'd go full steam ahead on the project. You can always pull your niche testing app later.