I agree, and I bought plenty of both paid and open source apps in the past. But I find that having the source code offers stronger guarantees than a receipt (so

I agree, and I bought plenty of both paid and open source apps in the past. But I find that having the source code offers stronger guarantees than a receipt (some paid-for proprietary software also let me down, if only for becoming abandonware), that's why I only use proprietary software if it's in a comoditized niche with plenty of interoperable alternatives. For instance, I bought every "simple mobile tool" app (from Tibor Kaputa) on the play store (even though I don't use Google Play, at least they are in my family library), as well as OSMAnd plus its plugins. I also bought some open source games on Steam, such as mindustry. Krita is there as well, but I prefer donating directly to KDE. I am totally in favor of paying devs, though I generally prefer to make anonymous donations, trough liberapay (unfortunately not tax-deductible) for instance, as a way to cut the middle-man, (I tend to spend more than 600€ a year on free software donations, which is not negligible to me: almost half a monthly salary). I don't really understand your point, to be honest: ES is "abolutely proprietary" as far as I know, so it won't be available on F-droid. I was trying to come up with examples of proprietary software that changed under me. Source access is a must for me, this is about freedom, not price. I also have trust issues with proprietary software.