We have just released a FREE plugin: Welcome GUI! Find it in the “NEW/ALL” Category.
Use /setguiwelcome <title/message/button> <text> to change GUI text.
Use the following codes inside messages to display custom data:
%online - All online players
%slots - Server slots
%name - Name of the player who joined
%n - Number of current online players
%line - New line
Spajk is a good guy