Less than two weeks after launching, simple (stupid?) messaging app “Yo” now has its first evenly matched competitor — at least among fans of author George R. R. Martin, anyway.

Inspired by hit HBO television series Game of Thrones, “Yo Hodor” is an iOS app that mimics the functionality of Yo, which simply allows you and your group of friends to communicate with each other using only the word “yo.” Except, the Yo Hodor app of course can only say “Hodor.”

Screenshots of newly launched iPhone app "Yo Hodor," a copycat version of messaging app "Yo" for Game of Thrones fans.

Above: Screenshots of newly launched iPhone app “Yo Hodor,” a copycat version of messaging app “Yo” for Game of Thrones fans.

If you’ve ever watched Game of Thrones, you’ll know that the word “Hodor” is actually the name of a lumbering, yet noble character called Hodor played by actor Kristian Nairn. Hodor communicates entirely by repeating his name a number of times, often changing how he delivers the line to match his emotions in any given situation.

Hodor the character is perhaps the original “Yo,” or at the very least an awesome pop culture metaphor for how two people are able to communicate using only a single word.

But as for the messaging version, the Yo Hodor app itself launched today and is available for free via Apple’s App Store. There’s also an Android app simply called Hodor on the Google Play Store that’s also free, but may not have come from the same developer. That means you probably won’t be able to communicate with smartphones running a different operating system, or even another Hodor copycat app from a different developer.

Since I don’t see any official mention of licensing by HBO or the startup responsible for the original “Yo” app, I’d suspect these may soon disappear due to copyright infringement. That said, download them while you can.