The core infrastructure for variable screen sizes and densities was introduced in Android 1.6 Donut (September 2009). There have been improvements with newer ve

The core infrastructure for variable screen sizes and densities was introduced in Android 1.6 Donut (September 2009). There have been improvements with newer versions (e.g. more sizes and densities), but that's straightforward to deal with. The other big improvement was the Fragments API that came with Android 3.0 Honeycomb (February 2011), but that came with a compatibility library that worked all the way back to Donut. And it was more about decomposing your UI into components that could be arranged differently for phones and tablets, not about adjusting a single UI within a device class.