How does my UI be compatible with other screen or mobile devices versions? Is there any code that must be added on the manifest xml?
Use Android Asset Studio 9 Patch Generator to create images for various screen resolutions, and use Android Asset Studio to generate your icons as well: https://romannurik.github.io/AndroidAssetStudio
Try to avoid fixed dimensions in your layout. Instead use match_parent, or wrap_content.
You may optionally consider to add additional layout files for default landscape devices such as tablets, or for devices over a certain resolution. So in your res folder you have a layout folder, and optionally you could have layout-land, and layout-sw720dp folders. You can make copies of your XML layout and then start making changes from there for the layout-land and/or layout-sw720dp folders.
Essentially here is the same advice in the Android developer documentation: http://developer.android.com/training/basics/supporting-devices/screens.html