Please note this is a WIP. More information, more complete information, and more sources to come.

Installation

To install:

Repositories

Repositories are where the flatpaks are to be distributed and thus downloaded from. Very much like a rpm or deb package repository.

Runtimes

Runtimes are the software base that a flatpak is created on top of. Generally these will be pulled in when you install a flatpak. Not the case for developers, as you will need to choose which one(s) to work with, and install the one(s) manually.

The best starting spot to learn more is to visit : http://flatpak.org/runtimes.html

Once read up the next logical thing is to add GNOME & FreeDesktop.org :

    flatpak remote-add --from gnome https://sdk.gnome.org/gnome.flatpakrepo

References