Every time I have an idea, I write it down. These are a collection of my top software ideas -- problems I think enough people have that don't have solutions. I expect you can reach a decent userbase if marketed correctly, as I am surely not the only one with these problems.
Why do you think that https://github.com/danistefanovic/build-your-own-x is a good alternative to ideas-for-projects-people-would-use