Works for all WoW client versions!
This addon lets you perform perfectly synchronized emotes with your party or raid members by writing a chat command. Everyone who participates needs to have the addon installed.
Commands (write them in chat):
/esync - Shows all commands.
/esync 0/1 - Write 0 to disable the addon and 1 to enable the addon.
/esync EMOTE - Replace EMOTE with the desired emote, for example: "/esync dance". Everyone will perform the emote with your current target as the emote target.
Source: https://github.com/techiew/WoW-Addons