What is it?

its a simple plugin to change Join/Quit message

in Game or in Config

Usage

Changing join message

/setjoinmessage "Message"

Or use the config 

changing quit message

/setquitmessage

Or use the config

Perms

Join cjqm.join

quit cjqm.quit

Addons

For using color codes u can use

\u00A70 - BLACK
\u00A71 - DARK BLUE
\u00A72 - DARK GREEN
\u00A73 - DARK AQUA
\u00A74 - DARK RED
\u00A75 - DARK PURPLE Etc etc

Or §

U can use %Player% for the playername

Am I allowed to decompile it?
No, you are not allowed to decompile!