RoundCube skinbuilder is now as part of WKApp Builder developer tools, there is no limit you can design your own skins very simple there is no code knowledge needed, create your favorite skin you can watch the video tutorial to see how simple it is to create a beautiful skin, I will extended the builder still more during the next weeks, as adding options like drag and drop, wkapp builder will be open in march 1. I will share some skins for free, the soonest I check that there are no errors.
fell free to contact me.
Video preview in youtube.
https://youtu.be/VPKDiwAzVS8