(Update) in patch 7.1 you now also need use this cvar (character-specific!) to show friendly NPC nameplates, but their name are shown by default so this addon is now obsolete

/run SetCVar("nameplateShowFriendlyNPCs", 1)

Gives a name to nameplates

• With the Hostile, Quest, and Interactive NPCs option you can get nameless nameplates. This addon adds the names back to the nameplates.
• With the All NPCs option you get nameplates with names, but you will always see names from any NPC from any distance.

• If the Always Show Nameplates option is disabled (default), nameplates are only shown for NPCs that are in combat / targeted. If you want it to be like in Warlords of Draenor you can enable it.