Xperia™ Theme Creator Make your own theme with our free Xperia™ Theme Creator available for PC, Mac and Linux. Follow the link to get started: https://developer.sony.com/develop/smartphones-and-tablets/theme-creator/get-started/
If you publish your theme on Google Play, we recommend that you clearly state in the description that it is a theme for Xperia devices, and that you include the string “Designed-with-Theme-Creator-for-Xperia” in your description – in order to make it easier to find your theme. However, please note that you are not allowed to use Xperia or Sony in your theme title, package name, or any included graphical assets without explicit permission from Sony.
If you would like to know how the XPERIA™ Magical Winter Theme was made - originally with the Theme Creator v1.3 - you can watch the following tutorials: