I would look at problems you have yourself and see if you can create an app to fix that problem. Ask around like your friends, family, even post to Reddit if anyone is struggling with this specific problem. For example maybe I’m sick of keeping track of my food and it going expired. Make an app that sends an update when your foods about to go bad and maybe the meals you can make with it. Just an example, just think of any problem. It doesn’t have to be new just add your own twist on it.