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.

Ghostwriter, free and open-source markdown text editor, released version 2.1.0 with some new features. Here’s what’s new and how to install in Ubuntu.

Ghostwriter is a cross-platform, aesthetic and distraction-free Markdown editor works on Linux, Windows, and MacOS. It comes with live HTML preview, dark and light mode, focus mode, hemingway mode, autosave, MathJax, and built-in Cheat Sheet in the sidebar (toggle via F1) in case you forgot some Markdown syntax.

By releasing v2.1.0, it now auto-saves untitled documents to a draft folder, and provides a button in ‘Preferences’ to open that folder (it’s user Documents folder in my case).

And, it loads the last opened file on startup while providing an option to toggle on/off this feature. The bottom status bar can now display a different statistic. By clicking on it, you may choose to display how many words, characters, pages, sentences, paragraphs, or read time, write time, wpm, etc.

How to Install The Latest Ghostwriter 2.1.0 in Ubuntu:

The text editor has an official PPA that so far supports for Ubuntu 20.04 and Ubuntu 21.04. The Ubuntu 21.10 package is somehow not updated at the moment, you may check the link page though.

1.) Add the PPA:

Press Ctrl+Alt+T to open terminal. When it opens, run the command below to add the PPA repository:

sudo add-apt-repository ppa:wereturtle/ppa

Type user password (no asterisk feedback) when it asks and hit Enter to continue.

2.) Refresh system package cache by running command in terminal. This is done automatically in Ubuntu 20.04 & higher while adding PPA, but some Ubuntu based systems may not.

sudo apt update

3.) Finally install ghostwriter via command:

sudo apt install ghostwriter

The software team also maintains Copr repository for Fedora 33/34/35 and rawhide users. Simply open terminal and run commands below one by one will install it in Fedora:

sudo dnf copr enable wereturtle/stable
sudo dnf install ghostwriter

Uninstall Ghostwriter:

To remove the markdown editor, open terminal and run command:

sudo apt remove --autoremove ghostwriter

And remove the Ubuntu PPA using “Software & Updates” utility under Other Software tab:

KGX is a simple and user-friendly terminal emulator for GNOME. It aims to be a “Core” app for GNOME and Phosh, graphical shell for mobile devices like Purism’s Librem 5.

Rather than replacing GNOME Terminal, it’s on target to serve casual Linux user who rarely needs a terminal to carry out simple command line tasks. Via libhandy library, the terminal adjusts nicely to small screen sizes and for touch usage.

KGX terminal emulator. Image from

The name KGX is the station code for King’s Cross, the London terminus of the East Coast Main Line. The app is available in Ubuntu repositories since Ubuntu 21.04, though the package version is lag behind.

The stock KGX in Ubuntu 21.10 has a semi-transparent app window and the UI looks kinda like Gnome terminal. Though it’s lightweight and has less features.

KGX in Ubuntu 21.10

Install KGX in Ubuntu 21.10 / 22.04:

For Ubuntu 21.04, Ubuntu 21.10 and next Ubuntu 22.04, it’s easy to try out this terminal emulator by pressing Ctrl+Alt+T on keyboard, and then run command in terminal to install it:

sudo apt install kgx

Then, search for and open the terminal emulator from activities overview.

While the stock package is always old, you may build it from source which is available at KGX project page.

Linux has quite a few image annotation tools. “Annotator” is the one designed for Elementary OS with specific features. Here’s how to install it in Ubuntu 20.04, Ubuntu 21.10, Ubuntu 22.04 via PPA.

Without using GIMP image editor, I sometimes uses Shutter to annotate image quickly. As well, Ksnip has some useful tools (e.g., drop shadow, invert color and add border) that I use regularly.

Annotator is an app looks kinda like MacOS Preview. Like other tools, it allows to add text, rectangle, ellipse, sequence number, line, arrow, blur effect, crop and resize image. What makes it different is the “Magnifier” tool. It adds a circle on your image and enlarge the area inside. By right-clicking on the circle, it offers option to change magnification.

Also, it allows to add stickers, such as industry, mobile and data icons, different type of arrows.

Install Annotator in Ubuntu:

Though the app is designed for Elementary OS, it works on other desktop environments. The developer team provides official package as Flatpak. Make sure the flatpak daemon is installed, you may then install the app via command:

flatpak install

However, the Flatpak package requires separated Elementary OS platform and SDK as run-time libraries. The run-times take about 700 MB space while the app itself is only a few hundred KB.

So I created this unofficial Ubuntu PPA for those want to try out this annotation tool with native DEB package. So far, Ubuntu 20.04, Ubuntu 21.04, Ubuntu 21.10, and Ubuntu 22.04 are supported.

1. Add the PPA

Press Ctrl+Alt+T on keyboard to open terminal. When it opens, run commands to add the PPA:

sudo add-apt-repository ppa:ubuntuhandbook1/annotator

Type user password, no visual feedback, when it asks and hit Enter to continue.

2. Update package cache

Ubuntu 20.04 and higher refresh system package cache automatically while adding PPA, but some Ubuntu based systems may not. To do it manually, run command:

sudo apt update

3. Install Annotator:

Finally, install the app using command:

sudo apt install com.github.phase1geo.annotator

Once installed, search for and open it from start menu (activities overview) and enjoy!

Remove Annotator & Ubuntu PPA:

To remove the Ubuntu PPA, use command:

sudo add-apt-repository --remove ppa:ubuntuhandbook1/annotator

And remove the annotation tool via:

sudo apt remove --autoremove com.github.phase1geo.annotator

For spaceflight enthusiasts, there’s now a GTK4 app for Linux Desktop and Phone (e.g., PinePhone, Librem 5) to keep track of upcoming rocket launches.

It’s “Space Launch”, an open-source app gets data of the launches from The app displays the next upcoming launches with information about the company and/or manufacturer, such as Rocket Lab and SpaceX. The location, date and time, and count down for the rocket launches.

Dark mode is supported and it may show more launches as schedule.

The app is currently in alpha release. More features will be added later. And it’s compatible with Linux Phone using Phosh.

Install Space Launch in Linux:

This app is available to install via Flatpak package. You may follow the steps below one by one to setup flatpak daemon and install Space Launch.

1.) Press Ctrl+Alt+T on keyboard to open terminal. When it opens, run command to install the Flatpak daemon:

sudo apt install flatpak

The old Ubuntu 18.04 and Ubuntu 16.04 may also install the app, though need to add Flatpak PPA first.

2.) Next, add the Flathub repository that hosts the packages via command:

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

3.) Finally, install the app using command:

flatpak install flathub org.emilien.SpaceLaunch

The app package itself is about 75KB. Though, if you’re first time installing Gnome App as Flatpak, it may also install the run-time libraries take up a few hundred MB disk space.

After installation, search for and open the app from ‘Activities’ overview screen and enjoy!

How to Remove Space Launch:

To remove the app, simply run command in terminal:

flatpak uninstall --delete-data org.emilien.SpaceLaunch

And you may clear unused run-time libraries via command:

flatpak uninstall --unused