Profitable Application Idea

I am currently looking for a mobile application idea. The application can be about anything (food industry, utility, game, entertainment) that can be widely used and downloaded through the mobile store (either apple or android or any store).

This is not an academic paper. I do not need intros and conclusions and referencing. All I need is multiple mobile application ideas that can have massive downloads and have high profit potential.

The app can generate profits from adds and sponsorships, so the app doesn’t have to have payments like subscriptions.