If you haven’t gotten your fix with Mortal Kombat 1, the mobile app Mortal Kombat Onslaught is available to get your fighting fill. However, players have reported issues with it since its launch ...

You don't even need the actual app to do this. It is very simple and it only takes a few minutes to do. This glitch works on PS4, PC, and Xbox One at the moment which is 5/15/2015.