Horse armor lives on!
PC now has access to the Fallout 4 Creation Kit, an official set of tools allowing players to mod anything from the environment, quests, weapons and more. Along with this is a hub centered around easily finding and installing the mods, which will be available from the game menu.
Access to supported mods will also be coming to consoles, arriving on Xbox One in May and PS4 in June.
Source-Bethesda.net