Look, not every tip needs to be about extending battery life or accessing things more easily. Today we've got some smiley faces and stuff. It turns out you can use Emoji in homescreen folder names, which is neat.
Just pop open a folder and tap on the title like usual, then (on the Google Keyboard) long-press the 'Done' button to switch to Emoji. This might be different if you're not using the Google Keyboard, though. The only issue you have to deal with is a weird rendering quirk when the folder is closed – a few dark lines behind the Emoji. It looks a little odd, but it's not as noticeable on all images. There's a bug in the issue tracker for it.
This works best on Android 4.4, which has proper support for colorful Emoji, but you might have some luck with Android 4.3 as well. Have fun.