Flappy Bird on Windows Phone 8
Its a third-party port (unofficial) in the WP8 Store by IG Mobile. Try it out on your WP8 device by clicking here.
It is insanely addictive but will make you rage quit in 10 minutes! Install at your own will.
21 46 is my best score to date.
(photos are screenshots captured on my Nokia Lumia 1520)