The easiest way to install and update Flatpak applications is using a dedicated software management app, like GNOME Software. Several distributions allow this, including Fedora, openSUSE and Arch. If this graphical solution isn't available, then it is still possible to install and manage Flatpak applications from the command line.
If you are using the command line, the applications page includes the commands that are needed to install each application. This guide includes additional commands that you can use to manage those applications once you have installed them.
To list all the Flatpak applications that you have installed, run:
$ flatpak list
Application names are given in reverse DNS format - like a reversed web address - with three parts separated by dots. This is a unique identifier that is used throughout Flatpak.
Once a Flatpak application has been installed, it can be launched in the usual way from your desktop. Flatpak applications can also be run from the command line, though:
$ flatpak run APPLICATION
APPLICATION should be replaced with the name of the application that you want to launched, in the standard reverse DNS format.
Uninstalling an application is a simple command very similar to the
$ flatpak uninstall APPLICATION
Updating all your installed applications with FLatpak is a single command:
$ flatpak update
It is also possible to update an individual application by adding its name to the command:
$ flatpak update APPLICATION
With Flatpak, repositories can include one or many applications. They can either be added manually or as part of installing an application. To list the Flatpak repositories that you have added, run:
$ flatpak remote-list
It is then possible to list all the applications in each repository using:
$ flatpak remote-ls --app REPOSITORY
REPOSITORY should be replaced by the repository name given by
flatpak remote-list. The
--app option means that only applications will be listed. Without it, runtimes that are provided by the repository will also be listed.
Finally, it is possible to remove a repository using:
$ flatpak remote-delete REPOSITORY
Runtimes are collections of dependencies that are used by applications. They are provided by repositories, in much the same way as repositories of packages. When installing an application, Flatpak will automatically install any required runtimes if they are available. This does require that the repositories containing those runtimes are added first.
In most cases, the GNOME SDK repository contains all the runtimes you might need. To add it, run:
$ flatpak remote-add --if-not-exists gnome https://sdk.gnome.org/gnome.flatpakrepo
--if-not-exists means that the repository will only be added if it isn't there already and
gnome is the name for the repository.