ADD flatpak

Install Flatpak

To install Flatpak on Ubuntu 18.10 (Cosmic Cuttlefish) or later, simply run:

      $ sudo apt install flatpak
    

With older Ubuntu versions, the official Flatpak PPA is the recommended way to install Flatpak. To install it, run the following in a terminal:

      $ sudo add-apt-repository ppa:alexlarsson/flatpak
      $ sudo apt update
      $ sudo apt install flatpak
    

Install the Software Flatpak plugin

The Flatpak plugin for the Software app makes it possible to install apps without needing the command line. To install, run:

      $ sudo apt install gnome-software-plugin-flatpak
    

Note: the Software app is distributed as a Snap since Ubuntu 20.04 and does not support graphical installation of Flatpak apps. Installing the Flatpak plugin will also install a deb version of Software and result in two Software apps being installed at the same time.

Add the Flathub repository

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
    

Restart

To complete setup, restart your system. Now all you have to do is install some apps!