Thank you guys so much for 18 downloads in about two days! I am coming out with a new plugin (cant say the name) very soon! NumberGuesser is a fun, simple, and open source minigame for Minecraft 1.8 and (untested) below! NumberGuesser is easy to use and setup! There are very few permissions, and pretty straightforward commands.
Source code: (Educational purposes): Coming Soon
Good luck with your server!