Pocket Uno 1.63 for Windows Mobile

Pocket UNO is a very good adaptation of the popular card game called UNO. Pocket UNO is the Windows Mobile version and it's totally free.

Rules of Pocket Uno are very easy and simple, The deck is by cards of 4 colors and the range of each color is 0-9 (red, blue, yellow and green) and a few action cards with special actions, a total of 108 cards.

At each turn, the player has to play a card from his hand that matches the color or rank of the top exposed card, or play a wild or wild draw four. If the player has no legal card to play, that player draws the top card of the stock, and may either play it or place it in their hand.

The goal is to rid yourself of cards before opponents do.

You can choose the difficulty level (easy, regular, difficult), animation speed...

It's totally free and very funny, so it's one of the best to choices if you want to play on the go.

Note:
You can read UNO rules here