As with the thread on the PC, lets share any deals for games that can be obtained for free.
The first game for the thread is SteamWorld Dig which is free on Origin. It is an excellent game with a sequel soon to be released. You'll need to create an Origin account, but that is free.
This deal will only be available for a limited time and doesn't require you download the game, so i'd act sooner rather than later if this is something you're interested in playing.