XPBroadcast is a plugin which automatically sends a message to all players on the server when a player reaches a certain level. It is easy to set up and will work out of the box.
To install XPBroadcast you just put the .jar file into your plugins folder.
XPBroadcast is pretty easy to customise. After you put the .jar file into your plugins folder and reload the server there will be a XPBroadcast folder with a config.yml file in it which will look like this:
# XPBroadcaster v1.0.0 by bubbl3gumtea Level: - 50 - 100 Message: Player %player% reached level %level%.
To add a level which gets broadcasted to the plugin you just add "- <level>" Between the "Level:" and the "Message: [...]" line. To change the message the player receives just change the text after the "Message: ". The player name is represented by %player% and the new (achieved) level by %level%. If you want to put a colon (:) into your text you have to put the whole text into double quotation marks ("). Currently there is no way to write "%player%" and "%level%" as literal strings.
If you happen to find a bug in the plugin do not hesitate to contact me.