You need to be able to use Flash on your device. If your device doesn't support Flash, download Puffin Web Browser. You will have Flash for a certain amount of days. To continue Flash after this date, share the friend code given to you in the Flash notice, or buy the full version of Puffin. On the computer, press space to begin. On your mobile device, wait until the message disappears. Tap the cards on the sides to cycle through your cards, and tap the one in the middle to select it. On your mobile device, NOT THE COMPUTER, tap the green flag to shuffle a new deck.
If you don't have a mobile device, or another computer, open 2 windows. Should work fine. I'm just testing cloud variables. Would probably only work properly if only one player using 2 windows on the same computer or a computer and mobile device were using the project. I was inspired by http://playbrassmonkey.com/ to make it.