Just a weakaura that help me to see the number of wind arrow shot from Legacy of The Windrunners and allow me to preshot the focus bonus and Aimed Shot charge gain from the talent.
The talent gives 30 focus point and one charge of Aimed Shot every 24 winds arrows.
The weakaura will play a sound when your Aimed Shot shot will proc this talent.
You'll have to know that there is a long delay between a Aimed Shot and the four Wind Arrow proc.
If you reload your UI, it will break the wind arrow counter. It will be fixed when the proc occur because it reset the counter I use in the WA. I don't have clues if it's possible to get the internal arrow wind counter that blizzard use to give player the bonus focus and Aimed Shot charge.