Employers aren't going to care that you built a clone of (insert something here) that has 0 active users and just sits in a Github repo.

If I were interviewing you, I'd care more that you built something regardless of how many users it has, or whether it has any at all. Take this anecdote for what it's worth.

I've also tried the whole "make something you would use" and wind up finding out someone has already done it and better than I could do it.

I can't help but suspect you're limiting your own thinking somehow, in regards to the class of things you would use. There's no way everything that you could possibly use / find useful, has already been built. And even if it has, so what? Surely there has to be some quirk or annoyance to the existing solutions that you'd like to work around, or some missing feature you'd like to implement?

Heck, if nothing else, build a tool for helping you come up with ideas for things to build. Yeah, it's kinda meta, I know. But seriously, go find one of the slew of books out there on "how to spark your creativity" or whatever, and then translate their methodology into a tool that gives you a "seed" idea and then walks you through their various little brainstorming ideas. Gather your "seed" ideas by using some NLP to mine Reddit or Twitter (or HN), etc.

Or not... it's just a throwaway idea. But the point is, whatever you're thinking about, or whatever is bothering you, think about someway to build a solution to help you with that.

Sometimes I build small utilities for myself. Even small projects count. Sometimes those lead you down more interesting or challenging paths as well. You definitely don't have to build a popular web app with a big userbase (a big user base might even be seen as a distraction by your potential employer). Even just something that simplifies your life and you're the sole user of shows something. Most engineers are more interested in just seeing how advanced your dev skills are and how much you know / follow best practices.

The way I find side project ideas easily (and get swamped by them) is by:

1. Getting involved in multiple activities - I am part of a choir, I play board games with my friends, I read a lot of books, I take photos of the night sky and I like to do my own statistical research on various topics (e.g. politics).

2. Figure out the problems you face in all of these activities - I have found plenty, such as choir members who can't read music, lack of strategy analysis for various board games, lack of pretty astronomical software, lack of graphical representations of ideas presented in books and vast lack of graphics representing the effect of political policies.

3. Figure out which of the problems can be solved with software.

4. Pick the languages/frameworks/tools you want to learn to use and that will help you with the project.

5. Build an MVP.

6. Invest more into the project, or otherwise repeat 1-5.

You can see some of my projects on http://www.michalpaszkiewicz.co.uk to get a gist of the weird things I end up doing.

Edit - wth is up with the formatting here

I created side projects as businesses and used older tech because I could get it done faster and interviewers looked at it as a negative. I was more "business" oriented. If the goal is a better job look at job descriptions and do a project with the tech in the job descriptions.

I'm happy to make clones, just to learn how things work. I made a bitcoin clone and now I am working on a deep learning framework clone.

I think the real gain you get out of a side project is the experience and knowledge, which you could carry with you. Not really the side project itself.