Timetaco lets you easily create your own countdown with custom background + Unsplash and push notifications!
Countdown Screensaver is a Mac OS X screensaver to countdown to your big day. Minimalistic design, useful, and 100% free.
Hurry is an app for Android that creates beautiful countdowns to the days and events that you look forward to in the form of beautiful widgets.
Countdown is a simple, no-frils way to track upcoming special events. Track things like your next vacation, the weekend, your anniversary, or whatever else! Be creative and take joy in telling your coworkers exactly how long you have until you all leave the office on Friday.