This is my implementation of iOS's segmented controls for Android by extending RadioGroup and RadioButton. Example project included.
For text-only buttons, you just need SegmentedRadioGroup.java which extends RadioGroup, so all your standard RadioButton implementations and callbacks should work.
For image buttons, implement SegmentedRadioImageButton instead of RadioButton.
Drawables are included, but can easily be replaced.
See example project for usage
SegmentedRadioImageButton currently uses a custom implemented scaleType similar to CENTER_INSIDE and doesn't respect padding values. If anyone wants to extend the onDraw method to do so, that would be much appreciated.
RadioGroup has a bug that calls onCheckedChangedListener multiple times when you use clearCheck() or check() programmatically. See this for more info, and this for a possible workaround.