For Ubuntu 18.04 and higher users with multiple monitors, Hydrapaper is a GTK utility allows to set different background wallpaper for each monitor in Gnome 3, MATE, or Budgie desktop.
The utility uses Pillow to create a single image merging all of your chosen wallpapers and setting it as your wallpaper with the “Spanned” option.
Hydrapaper can be installed in Ubuntu 18.04 and higher via Flatpak (Containerized software package). Open terminal either from application menu or by pressing Ctrl+Alt+T. When it opens, do:
1. Run command to install Flatpak deamon first:
sudo apt-get install flatpak
Type user password (no asterisk feedback) when it prompts and hit Enter.
2. Then add Flathub repository via command:
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
3. Finally install the utility via command:
flatpak install flathub org.gabmus.hydrapaper
Like normal software package, open Hydrapaper from application menu once successfully installed on your system.
To uninstall the utility, run command in terminal:
flatpak uninstall org.gabmus.hydrapaper