Any Shopify devs, what have you built as a service or product?

Kind of curious what you've built.

I'm looking to learn their API/build products eg. API connectors or something like that. I'm a developer by day, crying person at night(dreams of that financial independence).

Just wondering how is it, crowded market? I intend to cruise through forums looking for problems and build them(I've heard that's a bad premise) but I'm not a business person so don't know of problems off hand.

I also had some thoughts about your work just getting blatantly stolen, if someone buys the app or whatever. Packages it as their own... which copycats exist but make it better etc... but you could source where it came from by adding unique per-purchaser hashes I guess... but maybe not possible with how apps are released... but yeah that's a good problem to have I suppose.