Minecraft wiki entry for Development_versions, associated text: Upgraded the rendering system to use OpenGL ES 2.0 (coming from 1.1), using OpenGL 3.0 where available.
Ported tinted lighting from Java Edition.
Ported the round fog from Java Edition.
Some performance increase on most devices.
Mesa biomes have gold at every elevation and can spawn mine shafts on the surface.
Added dust particles falling from unstable gravel and sand.
Added more wood types for fences and gates.
Added adjustable brightness (gamma) setting to adjust the darkness of dark terrain.
iOS: Added a 64-bit build for compatible iOS devices.