This repo holds slackbuilds to build the latest version of Flatpak.
Flatpak allows easy installation of software that is either missing from the Slackware repos or difficult to install. Examples include Libreoffice, Steam, VLC, Spotify and so on. See flathub.org for available titles.
Once everything is installed you simply
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
and you're off to the races. flatpak search to find software, flatpack install to install, etc. See man flatpak for details.
There's an intermittent issue with the flathub repo reporting error 7, no connection.
So for this version, flatpaks cannot be installed with
flatpak install [application-id]
Instead use
flatpak install flathub [application-id]
If Rofi doesn't list flatpak installs, try changing the key binding to rofi -show drun