Over and all, you need to create different layouts/drawables for supporting all the screens. It depends on your requirement, say for example, if you would want to include 2 buttons in small screen and 4 buttons on large screens then obvious you have to create different layouts.
If you would want to display same number of buttons in all screens then I would suggest you to prepare different set of images/drawables and include them in your project. Here you don't need to do anything other than placing images in particular drawable folders.
One more thing, If its a plain background then you can create 9-patch image so that it can stretch with whatever size you want or your device supports.
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