Some consumer electronics seem to be designed for a level of consumer where a screwdriver is hard to come by, so the screws are designed to be screwed in with coins instead.

I've got a few: previous generation apple bluetooth keyboards (though these are like 1 full turn to undo, not terrible). Some playstation accessories, like the PSone screen addon, and the PS2 network adapter.

I found myself swapping hard drives in the PS2 one too many times and got annoyed with using a coin to remove the network adapter.

This is a plastic holder for a penny, to give you a decent sized handle, but still have a coin to interface with the screw

NOTE: this is designed specifically for screws that use coins. Trying to use this for normal screws will result only in disappointment. This is a terrible normal screwdriver.