This is a very simple plugin that sends a chat message to a player whenever he joins (i just did this for a friend thus i won't update it, but if you need something else lemme know it). The message is defined into the config file.

Placeholders:
{player} = Player's name.
{time} = World's time (format 24h).
{onlineNum} = Number of online players.
&nl = Creates a new line.

Colours:
Standard minecraft chat colour codes are supported.

Example.
OnJoinMessage: "Hi {player} and welcome on this server. &nlAt the moment there are {onlineNum} players on line and it's {time}. &nlHave fun!"