There are some unofficial map themes for Marble which are distributed via Git archives. Casual users wanting to use them are confrontent with two problems: 1) they need to know the location of the maps on their computer, which depends on the OS and 2) knowledge how to use Git is required. If there was a GUI in Marble where a Git URL could be entered, this knowlege wasn't required any longer, making the task much simpler. Furthermore, Git allows for signalling updates of map themes to the user. The updates could be downloaded automatically in the background. Reproducible: Always