I killed the Ender Dragon (in survival), but I can't find the End Gateway. What am I doing wrong? I am playing on a PS3.
Since you created your world before the end city update you need to reset your end. You can do this through settings. This will require you to beat the Ender Dragon again but you will get an End Gateway.
You either have to reset your end or build >1000 away from central island
Sorry I wasn't very clear last time. From what i played, the End Gateways should be from 15 to 50 blocks away from The End (from what i found and iv'e been in The End 4 times, in different worlds and found one in each one of them), and once, even was on The End island. To spot it, build around a lot and look for the lights the End Gateway emits. They look like purple Beacon lights that go on and off.
I can't give more information, since i barely play Minecraft now (but i still do), so good luck in finding it.