The app was just updated with a number of new card designs, including more than two-dozen for Mother's Day, coming up on Sunday, May 13, 2012 in the U.S. There are 28 new Mother's Day cards and 28 new Get Well cards, along with a number of new cards in each of the other categories as well.
Each card is $2.99 when sent within the U.S. and $4.99 when sent to or from anywhere else, including postage. The Cards app is a free download from the App Store. [Direct Link]