Disable on-screen zoom controls
Up navigation from settings screen
Don't animate from chooser to gameplay screen when pressing back button
Keep background colour continuity

The screen shown while app loads should have the same background as the GameView.
Reduce GPU overdraw on entire gameplay screen by 2

http://www.curious-creature.org/docs/android-performance-case-study-1.html

Before/after: imgur.com/a/6rpeK

Dunno if it makes any real difference :P