Unfortunately I don't have any specific insights on which type of projects is likely to net you any money. So here's some unsolicited feedback instead, from mor

Unfortunately I don't have any specific insights on which type of projects is likely to net you any money. So here's some unsolicited feedback instead, from more general to more specific. First, I think that your priority right now should be getting a job (any job) instead of winging it as a solo developer. Going solo is already expensive enough, which doesn't make it the best idea when you are one step away from homelessness. Second, and assuming you are still going to do it, I suggest you dedicate some time to improve your personal website. I visited your website, which took me to your Twitter, which told me to visit your vlog. Your main homepage had no link to neither your books, your CV, nor your vlog. Fixing that should be quick. And finally, I deduct from your video and your Twitter bio that you are living in Germany. If you are living here legally then the Budesagentur für Arbeit can almost certainly provide you a list of open jobs. They won't be fun jobs for sure, but they'll keep you out of homelessness. You may also qualify for unemployment.