The Horizon icon is based on preferences-wallpaper and preferences-system-login
from the fabulous Newaita-dark icon set, licensed CC-BY-NC-SA-3.0 and available
on the World Wide Web at: https://gitlab.com/cybernix/Newaita.

The status icons are from the Papirus icon theme, licensed GPL-3.0-only and
available on the World Wide Web at:
https://github.com/PapirusDevelopmentTeam/papirus-icon-theme.

The cloud iamge used for the Qt UI's "Disk" watermark is from Michael Clarke
on Flickr, licensed CC-BY-2.0 and available on the World Wide Web at:
https://www.flickr.com/photos/michaelclarke/5605880926

The Balloon image used for the Qt UI's "Finish" watermark is from Crystal on
Flickr, licensed CC-BY-2.0 and available on the World Wide Web at:
https://www.flickr.com/photos/crystalflickr/190713106

The Party theme for Openbox is based on the built-in Mikachu theme, which is
licensed GPL-2.0+, the same as Openbox.