comments:
I like this folding stool from Walmart, I'm not sure if prices are the same everywhere but for me it was $11. Has a carry strap so you don't have to have a bag to put it in or anything. In my personal experience it's been way more comfortable than the little square folding stools you'll find on Amazon, I had one for a while and it was barely any better than sitting on the floor with how low to the ground it had me. Not comfortable for my knees (or butt, lol, those seats are tiny) and getting up was a bit awkward. The kind I have now is a much more natural height to sit on IMO.
I have this folding stool and it seems pretty decent so far. I used to have a little folding seat like the second one you showed but they're SO low to the ground, it was really uncomfortable on my knees as well as just kinda being too small to be comfortable, you can feel the frame too much IME. The triangle shaped seat is much nicer to sit on.