Archives For November 30, 1999

Have many Flatpak app packages installed on your Linux desktop or mobile? Here’s an app to install, remove, downgrade, and manage app data with a simple graphical interface.

Flatpak is getting popular in today’s Linux, and some (e.g., Linux Mint, Fedora, and Pop!_OS) even have it support out-of-the-box. User can install (or uninstall) a Flatpak package by either using system package manager or running a Linux command in terminal. And, there’s a popular graphical tool Flatseal to manage permissions for each app package.

For users who want to get more controls for their Flatpak app packages, there’s a free open-source tool warehouse available for choice.

Continue Reading…

This is a step by step beginner’s guide shows how to install (or uninstall) Flatpak App Package, including local .flatpakref file, in Ubuntu 24.04.

Flatpak is an universal package format that can be installed in most Linux with a sandbox environment. It’s a free open-source project developed by Flatpak Team, which has closer relationship to GNOME and Red Hat.

As a competitor, Ubuntu has its own universal Snap package runs in sandbox. Flatpak is NOT supported out-of-the-box in Ubuntu, but easy to enable!

Continue Reading…

This simple tutorial shows how to install Beta version of your Flatpak app package from Flathub Beta repository in Ubuntu Linux.

Flatpak now is one of the top popular package formats for Linux. It runs in sandbox, allowing to easily manage software permissions and installing latest apps without worrying about dependency issues.

Most software developers publish their Flatpak app packages through Flathub repository. And for testing purpose, Flathub also provides a Beta repository.

There used to be web page for browsing and installing beta apps. The page however does no longer present in the website, though  the beta apps are still installable.

Continue Reading…

For those hate Snap but prefer Flatpak, there’s now a script to automatically remove all the snap apps installed on your system, and install them back as Flatpak in Debian and Ubuntu.

It’s Unsnap, a free and open-source script written by Alan Pope and some other contributors. The man was an employee of Canonical (the company behind Ubuntu), and one of the developers of Snap.

As you may know, Snap and Flatpak are universal Linux package format run in sandbox. They make possible to run newer apps (or app in multiple versions) in Linux without worrying about dependency issue. However, they take more disk spaces since run-time libraries also sandboxed, and so far have limitations to interact outside of sandbox.

Snap is powered by Canonical. The client and runtime are open-source while the backend is proprietary. Flatpak is completely open-source, and RedHat is behind the project. And, the open-source community seems to (IMO) prefer Flatpak is bit more.

Use Unsnap to Convert your Snap Apps to Flatpak

Unsnap does NOT rebuilt your Snap apps as Flatpak. It automate the process to remove Snap apps and install equivalent Flatpak apps back. Which, is useful for beginners and advanced users who want to save time for searching packages.

Supported Systems:

According to the script content, it so far supports: Debian, Ubuntu (and its official flavors), Linux Mint, Pop!_OS, Elementary OS, and Zorin OS.

Working Process

The script works in two mode: default and auto.

It by default detects your system status and snap apps, then generates following new scripts:

  • 00-backup – script to run snap save to save current data of snap apps.
  • 01-install-flatpak – script to install Flatpak daemon.
  • 02-enable-flathub – script to add Flathub repository.
  • 03-install-flatpaks – script to install equivalent Flatpak apps.
  • 04-remove-snaps – script to Remove all the Snap apps.
  • 99-remove-snapd – script to remove disable snap. Though it may be installed back via a system update.

It may skip 01/02 scripts if you already installed Flatpak daemon and added Flathub repository. And, the scripts are quite simply and easy to understand for those have basic Linux command and programming skills. Then, you can choose to manually run all or any of the scripts accordingly!

The auto mode will generate the scripts and run all of them automatically!


The scripts so far supports 219 applications. Advanced users can add more apps support by editing the ‘applist.csv’ config file.

It won’t remove unsupported and excluded Snap applications, though they will be gone after running 99-remove-snapd script either manually or automatically.

The script can save current data of all Snap applications. But there seems no way to import them in the equivalent Flatpak applications. And, there’s NO script to undo the changes!

Download Unsnap and Run the script

1. User can either download Unsnap from github page, or open terminal (press Ctrl+Alt+T in Ubuntu) and run command:

git clone

Run sudo apt install git if git command not found.

2. After downloading the script, either

  • run cd unsnap to navigate to source folder and ./unsnap auto to do all the things AUTOMATICALLY in one command.
  • or run cd unsnap, then ./unsnap to generate the scripts for MANUAL use.

For manual mode, all the generated scripts are available in “log-202x-xxx” sub-folder.

Just run cd log-* command to navigate to that folder, then choose any script you want to run. For example, backup snap app data by ./00-backup.

As mentioned, there’s no script to undo the changes! You can safely remove the unsnap folder after all the jobs done!

This simple tutorial is going to show you how to add both flatpak and AppImage package format support, while Ubuntu does not support them out-of-the-box.

Like Snap, Flatpak is an universal Linux package format runs in sandbox. Many software developers provide their app packages for Linux through Flatpak. And, AppImage is a portable Linux package format. Just download the package, and click ‘Run’ (after adding executable permission) will launch the program.

Enable Flatpak Support in Ubuntu

Ubuntu is focusing on the native deb and snap support. The developer team has officially announced that they won’t support Flatpak out-of-the-box.

However, user has the freedom of choice to use any other source sources, including Flatpak.

1. To enable Flatpak support, first press Ctrl+Alt+T on keyboard to open terminal, and run command:

sudo apt install flatpak

Type user password (no asterisk feedback) when it asks and hit Enter. In case the command does not work, run sudo apt update first to update package index.

2. (Optional) Then, you can choose to add the Flathub repository, the standard repository that contains tons of applications as Flatpak. To do so, run command:

flatpak remote-add --if-not-exists flathub

When done, log out and back in to apply the variable environment change.

3. Finally, you can either go to and install any Flatpak application, by running the flatpak install command in the down-arrow menu beside “Install” button.

Or, install a local .flatpak (or .flatpakref) file by running command:

flatpak install ~/Downloads/file_name_here.flatpak

Enable AppImage Support in Ubuntu

AppImage is a non-install package format for Linux. Like some .exe or .msi files, user can directly click run .AppImage file to launch applications. Though, the ‘allow executing file as program’ option has to be enabled first in file ‘Properties’ dialog.

Ubuntu does NOT support AppImage out-of-the-box, due to switch to fuse3, while the file format requires the classic fuse2.

So enable AppImage is also easy. Just open terminal (Ctrl+Alt+T) and run command to install the fuse2 library:

sudo apt install libfuse2

After that, right-click on your AppImage file and click ‘Run’ to launch the application after enabled ‘allow executing file as program’ and enjoy!

More and more apps today publish Linux packages as Flatpak. Though the run-time libraries take hundreds of megabytes disk space, some apps are really good and useful.

If you have some apps installed as Flatpak in Ubuntu or other Linux like me, then Flatseal may be useful to protect your privacy by managing permissions in per app basis.

Flatseal is a stylish GNOME app that displays all the installed Flatpak apps in the left pane. By selecting an app, it displays the basic information as well as permissions with toggle buttons. The app has an adaptive UI that works great on small screen size, e.g., Linux Phone.

With Flatseal, you may configure following permissions for your Flatpak apps:

  • Network access.
  • Sound server access.
  • GPU acceleration to reduce CPU usage.
  • System file or user file access.
  • Send notifications.
  • System bus and session bus.
  • Print system, smart card, webcam, bluetooth access, and more.

Note: some options (e.g., inter-process communications and X11/Wayland windowing system) may be required for the app to work. Switching those options off may cause function issues, though you may reset them easily afterwards.

As some options are not easy to understand, you may press F1 on keyboard to bring up the ‘help‘ window, which contains the descriptions for each toggle option. And, if permissions are removed and somehow no longer possible to reset, run command below (press Ctrl+Alt+T in Ubuntu to open terminal) to clear the changes and restart Flatseal.

rm ~/.local/share/flatpak/overrides/com.github.tchx84.Flatseal

How to install Flatseal in Ubuntu Linux:

The app itself is available to install as Flatpak package. To try it out, you must have already installed some apps as Flatpak. If not, you need to install the daemon first. For Ubuntu/Debian based systems, simply open terminal and run command:

sudo apt install flatpak

Next, install the Flatseal by running command in terminal:

flatpak install

Or use the command below if you already added the Flathub repository:

flatpak install flathub com.github.tchx84.Flatseal

As you see in picture, the app itself is about 683 KB, while run-time libraries take more than 700 MB. The run-times (e.g., GNOME platform) are shared libraries though that can be used for other Flatpak apps.

Uninstall Flatseal:

To remove the app, simply run command in terminal:

flatpak uninstall --delete-data com.github.tchx84.Flatseal

Note: removing Flatseal won’t reset the permission changes you made for the flatpak apps. You have to manually clear the config files under “~/.local/share/flatpak/overrides” directory to restore them.

Using Flatpak apps in Linux? You may found that Flatpak app appearance does not change when toggling light & dark mode or switching to another app theme.

As more and more apps publish Linux packages via Flatpak, I have a few of them installed in my Ubuntu laptop. However, the apps stick to the light theme whenever I switches to dark mode in Appearance settings.

Since Flatpak runs in sandbox and does not have permission to access the “/usr” directory, it does not use system theme according to the document. So, some popular GTK themes are packaged as Flatpaks. And, it detects the current system app theme and tries to install the Flatpak version of the theme if available during app installation or update.

I’m working with default Yaru theme in the most time, so it automatically installs Yaru theme flatpak package but leaves Yaru Dark not installed. When I switching to Yaru Dark, it can’t find the match theme so falls back to the default Adwaita.

Install GTK Themes in Flatpak:

As all I said, the solution is install the themes you use as Flatpak packages.

For Ubuntu 20.04 and higher that use the default Yaru app theme, press Ctrl+Alt+T on keyboard to open terminal and run command:

  • Install the Dark theme by running command:
    flatpak install flathub org.gtk.Gtk3theme.Yaru-dark
  • Or install the light theme if not exist via command:
    flatpak install flathub org.gtk.Gtk3theme.Yaru-light

There are also elementary stylesheet, Deepin GTK theme, Linux Mint’s Mint-Y in different colors, Arc, Numix, and other themes in Flatpak package format. You can find more themes via command:

flatpak search gtk3theme

Then install your prefer theme via “flatpak install flathub app-id” command.

After that, change app theme via Gnome Tweaks or System Settings to see the magic!

Make theme working for Qt apps:

Though I don’t have Qt applications as Flatpaks, according to the document, you need to open terminal and run following commands one by one to install the required runtime libraries:

flatpak install org.kde.KStyle.Adwaita
flatpak install org.kde.PlatformTheme.QGnomePlatform

That’s all. Enjoy!

This simple tutorial shows how to search for, install, remove, and manager Flatpak apps in Ubuntu Linux.

Flatpak is an universal Linux package format developed by an independent community. Like snap, it runs in sandbox and bundles most runtime libraries.

Flatpak is supported out-of-the-box in many Linux Distros, e.g., CentOS, Fedora, Linux Mint. And it’s available in the most Linux repositories. Since many software developers publish binary packages via flatpak, it’s a good choice to install external apps in Ubuntu Linux.

1. Install Flatpak daemon in Ubuntu:

Unlike Snap, the flatpak daemon is not pre-installed in Ubuntu. You have to first open terminal (Ctrl+Alt+T) and run command to install it:

sudo apt install flatpak

For Ubuntu 18.04, you have to first add this PPA repository before running this command.

Then add the flathub repository via command:

flatpak remote-add --if-not-exists flathub

2. Find for Flatpak App in Ubuntu: is the de facto standard for getting applications packaged with Flatpak. You can browse flatpak apps directly in the web browser via the link below:

If you use Gnome Software instead of Snap Store in Ubuntu, installing gnome-software-plugin-flatpak package will make Flatpak apps available in Software Center.

As well, you can search for an app via flatpak search TEXT. For instance, searching for an radio app via command:

flatpak search radio

NOTE the first time running this command takes quite a few seconds to update database.

3. Install Flatpak package:

If you find an app using the web page, then there are 3 ways to install it in Ubuntu.

Option 1. Click on the “INSTALL” button to download the installer file. Then open terminal (Ctrl+Alt+T) and run command to install it:

flatpak install /PATH/TO/FILE

Since downloaded files mostly save to Downloads folder. Type ~/Downloads/ and hit TAB key twice will show you available flatpak files.

In the case, the command can be:

flatpak install ~/Downloads/com.spotify.Client.flatpakref

Option 2. You can also right-click on “INSTALL” button and copy the URL link. Then install the app via command:

NOTE: It’s NOT the web page url, but the url link of the “install” button.

flatpak install URL

In the case, the command will be:

flatpak install

Option 3. In each app page, user can click the Down Arrow icon beside the “Install” button, where it provides the commands to install and run the Flatpak package.

If you found an app use flatpak search command, copy the App ID, then install it via:

flatpak install flathub App-ID

In the case the command can be:

flatpak install flathub com.spotify.Client

4. List installed flatpak apps:

For all the installed apps, you can simply run command to list them all:

flatpak list

To make it clean, only list apps via command:

flatpak list --app

And you can list installed runtime libraries, e.g., GNOME, KDE, QT platforms, via command:

flatpak list --runtime

5. Uninstall a flatpak package:

To remove a flatpak, you need to firstly get the App-ID via the previous steps. Then run command:

flatpak uninstall --delete-data App-ID

For instance, remove GIMP as the previous picture shows via command:

flatpak uninstall --delete-data org.gimp.GIMP

Removing flatpak apps WILL NOT remove the independent runtime libraries (QT, GNOME platforms, etc). You can run this command to get rid of them to free up disk space:

flatpak uninstall --unused

And to remove everything your installed, run:

flatpak uninstall --all

In addition for managing flatpak app permissions, try Flatseal.

For those who to install KDE’s Elisa music player, the official flatpak (containerised software package) is available for most Linux desktops including Ubuntu 18.04 and Ubuntu 16.04.

Elisa is a music player developed by the KDE community that strives to be simple and nice to use. We also recognize that we need a flexible product to account for the different workflows and use-cases of our users.

We focus on a very good integration with the Plasma desktop of the KDE community without compromising the support for other platforms (other Linux desktop environments, Windows and Android).

We are creating a reliable product that is a joy to use and respects our users privacy. As such, we will prefer to support online services where users are in control of their data.

How to Install Elisa player in Ubuntu via Flatpak

Open terminal either via Ctrl+Alt+T keyboard shortcut or by searching for ‘terminal’ from application launcher. When it opens, run following commands one by one:

1. First install Flatpak framework if not exist (For Ubuntu 16.04, add the PPA first):

sudo apt-get install flatpak

2. Then add the flathub repository:

flatpak remote-add --if-not-exists flathub

3. Finally install the Elisa music player:

flatpak install flathub org.kde.elisa

Once successfully installed, open the music player from application launcher and enjoy!


To remove the Flatpak package, simply run command in terminal:

flatpak uninstall org.kde.elisa

You may also remove the KDE platform runtime (sandboxed) via command:

flatpak uninstall org.kde.Platform

This quick tutorial shows you how to install the latest GNU Octave in all current Ubuntu releases via Flatpak packages.

Since there’s no stable PPA contains the latest Octave packages, Flatpak package is the easiest way to get the numerical computation software running on Ubuntu.

Similar to Snap, Flatpak is an universal Linux package format that runs in sandbox.

1. First open terminal (Ctrl+Alt+T) and make sure Flatpak support is enabled by running command:

sudo apt-get install flatpak

Old Ubuntu 16.04 & Ubuntu 18.04 need to add the Flatpak PPA first to install Flatpak framework.

sudo add-apt-repository ppa:flatpak/stable

2. Then add the Flathub repository, the best place to get Flatpak apps:

flatpak remote-add --if-not-exists flathub

3. Finally install most recent GNU Octave as Flatpak package from the Flathub repository:

flatpak install flathub org.octave.Octave

It will take a few minutes downloading the flatpak package as well as dependency platform if you’re first time installing it.

Like normal applications, you can launch Octave from Gnome app launcher:

The flatpak co-exists with traditional Octave package. You can alternatively run it in command line:

flatpak run org.octave.Octave


You can remove the Octave flatpak package by running command:

flatpak uninstall --delete-data org.octave.Octave

And remove flatpak support if you want:

sudo apt-get remove flatpak