Are you sure you had a confirm for Quoridor, and not some other game? The current version is 180420-1209, which indicates it's been around for a couple of years. Most games coded that long ago were done before confirm/undo buttons were common.
yes I confirm that there is a difference between the mobile and computer version. On the computer you can place the mouse in the right place without clicking to be sure to place your wall correctly. This is impossible on the phone. So the option to go back was implemented a few years ago on the mobile version .