I've come to a situation where I can't seem to think of any interesting problem to solve and that's terrible because I know the world is full of problems.
Start from a problem you have and work from there. If you don't have any (unsolved) problems then ask the people around you, you're bound to find something. But finding and solving a problem is half the work, the other half (and hardest part) is getting eyeballs on what you built.