Follow these simple steps to start using Flatpak
A flatpak package is available in Pisi 2.1 and newer. To install it, run the following as root:
$ sudo pisi it flatpak
Flathub is the best place to get Flatpak apps. To enable it, run:
$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
To complete setup, restart your system. Now all you have to do is install some apps!
Note: for now, graphical installation of Flatpak apps is not possible on Pisi GNU/Linux.