The Elytra wings arrived for PC Minecraft in October 2015, and they're a pain in the arse to find in game. Obtaining them involves going to The End, where be the Ender Dragon, and finding a flying ship where the wings are mounted on a wall.

What version was the Elytra added?

Elytra are one of Minecraft's coolest items and were added into the game alongside the 1.9 Combat Update. Elytra can be found in Minecraft's End Cities.

Is there only 1 Elytra per end city?

No. As long as you can access the end, you can generate new end cities. As long as you can reach a new end city, you can find an Elytra.