Appolous: Four letters: Who am I

For all of you who use Appolous, and have recently seen the Appolous troll, it is now asking a trivia question before you get in: "Four letters: Who Am I? ".

While I don't personally use jailbroken phones because they are a security risk and  stuff up your phone (slow it down) and app piracy is wrong, especially since developers don't earn nearly enough for the amount of work that goes in. Anyhow...  someone has passed on to me that the magic keyword to get in is kyek  so type that in as the four letter magic word.