Android 5.0 and Above Only! For this one, head to Settings > About Phone > Android Version. Tap on Android Version three or four times in quick succession. Then tap the colored circle that appears until it turns into a lollipop and says "lollipop". Then tap and hold the lollipop until the screen changes. You'll see cityscape, but it's actually an Android version of Flappy Bird, which starts when you tap on the screen again. Enjoy.