Android/iOS: When you're looking forward to an event, you can't help but get excited watching the days tick by. Countdown helps you keep track of everything you're looking forward to in one neat-looking app.
The app from timeanddate.com lets you add a large picture, set the date the event is going down and set its location. You can even add a widget to your home screen to show the current countdown on Android. It isn't as full featured as a calendar app would be, but then it's only really designed to do one thing, and it does it very well.
Countdown [Google Play Store]
Countdown [iTunes App Store]