I bought a piece of 1.5 inch stiff foam to try to fix a sag in a bed. It didn't work but having that thick piece of solid foam around has been a life saver.
Need something flat to put a laptop on? Throw it on the foam. Going to be doing something that requires you to be on your knees for a while? Get the foam!
It went from stupid purchase to something I'd gladly replace if it broke.
I'll check that out! They might at the very least have more there.
They also give you a cute "animal" profile for your sleep style when you pay. It was meaningless, but fun. I always got the dolphin during my free trial because I apparently have no idea how to sleep for more than 3 and a half hours.