First, make sure that you have GM9, FBI and a valid NAND backup. Then go to FBI and select the title keys option, it should bring up a page that has a bunch of numbers on the bottom screen, and the icon and title ID on the top screen. Scroll to the very bottom of the page to find DSIware (It should be in purple) and find the game, in your case UNO. Look at the bottom of the top screen to find a 16 character long number, write this down. Now boot into GM9 and choose SYSNAND TWLN/title/(the first 8 digits of that number)/(last for digits/characters of the number)/content. In this folder you will find the app file of UNO if you did everything correctly. Copy this to somewhere on your sd card and do what you will with it.