Like Flappy Bird, no one is really sure why Yo became so popular suddenly. The simple app only lets you send the word “Yo” to friends, and yet it received $1 million in funding and peaked at No. 3 on the App Store charts.
Fans of the hit TV show Game of Thrones on HBO should check out a better alternative to Yo called “Yo, Hodor.” Why? Because Hodor.