I created Emote Reply (9500 downloads) many years ago and last updated it in 2011. I never updated it for the new API until now. I also originally published it under the name of Umbridge. I tried to recover that account, but I couldn't. I just re-published it as "New Emote Reply."
What this addon does is allows you to set an emote reply. So, if someone targets your character and does an emote, you will reply with an emote in return. I set up most of the emotes with default replies. You can change them.
I also added code to remedy an endless loop issue that the original had. That was where when two characters targeted each other and one did an emote...and if you had the emotes set up just right, you both would spam the area with emotes until both characters got booted to the login screen.
Please let me know what you think...or maybe alternate ways I could have handled the logic to prevent the endless loop issue. Enjoy.