If you have a lot of free time and you don't mind chatting with people all over the world to kill boredom, then you might want to try this android app.

Fast Chat has lots of public chat rooms and you can join in on the conversation anytime. If you clicked with the people you're conversing with, you can invite them on a private chat where you can know them better without other people butting in.

The app requires no registration and you can chat anonymously. It is very easy to use and you can get the hang of it in no time.