Solve user problems
Pick areas such as dating apps, onlyfans etc and start earning 💸💸 People don't think twice in spending money on such products, especially when in those years when your hormones are kicking off.
That's where most spam also originates. Hormones are a common trap for hackers. Stay safe out there.
These things live very short life. I know a smal team of 3 members developers. Built app but got downloads 1milliom in a month. No ads or not even a great app. Just mentioned famous tik tok app name as prefix to their app and people downloaded. The moment Google identified, it was removed and everything gone overnight. Never restored.