NoSecondaryNames

Second names ruin your immersion? This addon hides them, so that in the world, chat, frames, lfg tool, you will see people as their first name only. 
Right click + whisper will still show the full name, as there could be people with the same first name.
Easily toggle on and off with the minimap button.
/nsn to open commands

-You need to have nameplates on to see one name on friendly players.
-Does not work on player nameplates inside dungeons due to Blizzard’s restrictions on addon access in instanced content.