android:layoutDirection

added in API Level 17

Defines the direction of layout drawing. This typically is associated with writing direction of the language script used. If there is nothing to inherit, "locale" is used. "locale" falls back to "en-US". "ltr" is the direction used in "en-US". The default for this attribute is "inherit".

Ensure to change the minSDKVersion to 17, or greater.

       android:layoutDirection = "ltr"
       android:layoutDirection = "rtl"
       android:layoutDirection = "inherit"
       android:layoutDirection = "locale"

ltr - Left-to-Right
rtl - Right-to-Left
inherit - Inherit from parent
locale - Locale

Resources:
http://developer.android.com/reference/android/view/View.html#attr_android:layoutDirection
http://developer.android.com/reference/android/R.attr.html#layoutDirection