This device actually keeps my phone cool to the touch. Not warm, but cool. I can play genshin and honkai impact on highest setting and not lose any frames.
I'm on the fence about how much I really need a phone cooler but it does work. Remove any cover you have and clip over where your phone gets hot and it will cool it off enough your phone feels cold on the screen opposite of where the cooler is.
I bought this out of a whim. Just to experiment and see if it will make a difference with my Samsung Z Flip3 5G. This device gets very hot since it's a 2 piece design and less thermal conductivity. This cooler is the real deal and got COLD to the touch in about 15 seconds.
For the price it's the best value and is quiet.
Oh mobile game I play is COD Mobile, at first I thought these were a gimmick but I just had to try one for myself, I was surprised how cold it actually gets! It helps keep my temps stable at 30c unlike before when my phone would get up to 37c playing max graphics!