PetaPixel is touting Cheetyr as the greatest Photoshop aid since they invented the graphics tablet, but I found it sadly lacking.
Basically, it's just another Photoshop shortcut cheat sheet, but has the added bonus of being searchable, but with less than 100 shortcuts, the search facility is going to have precious little advantage over scanning the (tiny) list. I tried testing it with the hidden FT Step & Repeat shortcut, but when that failed, I lowered my expectations, and tried Free Transform. Heck! Not even that was on the list. Anyway, here it is and if you are new to Photoshop, it might help. Forum regulars don't bother.
BTW It also has a similarly truncated list for Illustrator as well as CSS, Git and Vim, whatever they are.