You need to create xml files for different screen sizes
design your XML files to use references instead of hardcoded strings.
You can then assign a reference to layouts, buttons and so on which has a
different value depending on screen sizes.
android:padding="@dimen/pagepadding" instead of
android:padding="16dp" and define the dp in values/dimens.xml
To do that you have to create new folders in your Project like
values-sw600dp for devices with 600dp smallest width (like
Nexus 7 I believe) or
values-sw720dp-land for devices with the
smallest width of 720dp (10 inch tablets I believe) in landscape.
Do some reading on the developer page and on the internet for that. It's
not too difficult