Here's a simple weakaura that displays a box of buttons on your screen that allows you to quickly call out incoming enemy in Arathi Basin. Clicking on a button outputs a message to BG chat along the lines of "GM 3" or "GM Safe". It only gets displayed when in the BG.
If you find it useful and see my druid Tempeh from Ten Storms (now Tofued on Ashbringer) in a BG, say hi :)
Only tested on english language client.