I still get the occasional aspiring entrepreneur reaching out to me on LinkedIn asking me to build an app for them in exchange for free, or very nearly zero equity with no cash payment (like 0.05% of the product).

I usually don't respond, but occasionally I tell them that what they're doing is unethical at best. If they have an actual business plan then they can pay the person doing the lion's share of the work or at least offer a sizeable equity package.

I was about to write, I have seen this on occasion since I started my career (it's probably older, but that's when i became cognizant of it). I've had my first job as a programmer in 2001.