Where do I put the Settings button?
It really depends on your application, you could put them anywhere. However, considering most websites seem to have it in the top right corner, visitors may expect it there. I'd say left side wouldn't be bad - but putting it at the bottom is such a big change from the norm that you may confuse people trying to find it.
How to align a set of button to bottom of the screen in android?
Make the Parent of the LinearLayout containing the button as relative and set the property of linear layout containing two buttons as android:layout_alignParentBottom="true". You can also set the gravity of the Linear Layout to Bottom. Save this answer.