Holitapp is a very simple app. It lets you see upcoming (Canadian only) holidays and shows up information about that holiday, including a nifty countdown timer for each. You can even add your own important days into the list if you want. There are alerts as well, if you want to be reminded on that special day. Not missing are the social network sharing options.
The app features a vibrant red and black color scheme and has been pretty well designed. Holitapp is available for 99 cents on the App Store.