BG Messages is a very simple addon which enables you to quickly notify your fellow battleground players that your current location is safe, under attack or that a number of enemies are incoming. It was written for use in Arathi Basin, but may be handy in other situations as well.
Use: It's best use is to set the keybindings in the Keybindings interface. You can set three keybindings: one which (using /bg) tells your raid members that your current location is safe, one that it is under attack, and one which pops up a little window, in which you can enter the number of incoming enemies, after which the addon tells your raid members that the number of enemies you entered are incoming.
It also provides a command /bgmsg:
"/bgmsg safe" tells your raid members that your current location is safe,
"/bgmsg attacked" tells your raid members that it is under attack,
"/bgmsg attacked x" (fill in a number for x) tells your raid members that x enemies are incoming at your current location.
I finally updated it, so it's usable again for those who like it =)