Flathub contains over a thousand applications for the Linux desktop. Some are built by huge teams of developers, paid by corporations with deep pockets – like Google Chrome. Others are created by a one-person-band or a small team of independent developers, scratching an itch.
Many desktop Linux users are looking for the big names like Spotify, Discord and Skype, to service their needs, but there’s also a ton of relatively unknown applications. These unknowns might be lucky in a year to get the same number of downloads a corporate backed app gets in a day!
So we thought we’d shine a light on some of these lesser-known applications, to see if we can help raise their profile, get more users, and for the open source applications, perhaps convince users to turn into contributors. We can but hope!
We’re going to use the publicly available metrics from Flathub to identify applications which have single to double-digit downloads per day, as a measure of popularity. Some of them may have been quite popular at launch, or had “good days” in the past. The general rule of thumb for these posts is that the application gets less than fifty installs in a typical a recent day to warrant inclusion.
With that preamble out of the way, let’s dive in!
KopiaUI
KopiaUI is a cross-platform backup tool.

We’re always being told by the technical experts in our lives that we should keep backups of our important data. Well, KopiaUI seems like just the tool to get them off our backs! KopiaUI is a graphical frontend to the included kopia
command-line utility, abstracting away the numerous options to buttons and fields, making it more friendly for “normies”.
KopiaUI supports backing up to a variety of different locations it calls repositories, such as a local file-system, SFTP server, Rclone remote and WebDAV server. It also supports commercial storage providers like Google Cloud Storage, Amazon S3, Backblaze B2 and more.
On first launch KopiaUI guides the user through setting up a repository, password protecting it and then taking a first snapshot. While the user interface won’t win any awards for design, it’s functional and comprehensive. The graphical UI can even expose the underlying kopia
command-line options, should the user outgrow the GUI and want to drive things from a terminal, or schedule snapshots using other tools.
KopiaUI supports multiple repositories and different snapshots, and is very flexible about how and where to backup to. We think KopiaUI is a great way to introduce backups to users, even if it’s just to take a snapshot now and then to an external USB drive. Grab KopiaUI from Flathub, and backup something today!
Gittyup
Gittyup is a graphical front-end to manage source code projects held in git repositories.

To some, git is a mystery of baffling command line options. Gittyup aims to ease that pain with an easy to understand graphical interface. Gittyup can open existing local repositories, and connect to online repos at GitHub, GitLab, BitBucket and Beanstalk.
The interface has a light and dark theme, and can reflect the user selected desktop theme too. Functionally it’s very easy to pick up, with a clean interface that shows branches, committed changes, and diffs very clearly. Some of the most commonly used features are quickly accessible via a toolbar, with the rest in a series of menus.
There are plenty of graphical frontends to git available these days, but many are proprietary or lock some features behind a paywall. Gittyup is MIT licensed, hosted on GitHub and supported via LibrePay. If you’re like us, and git gets you all a muddle, try Gittyup over on Flathub, and see if that can help get control of your source.
Delta Chat
Delta Chat is a messaging app built on top of your existing email account.

Delta Chat‘s user interface will be familiar to users of Telegram or WhatsApp. It shares similar features such as image and audio file sharing, and the familiar conversation view. Where Delta Chat differs is there’s no backend infrastructure, no servers to spy on you and no accounts to create.
The reason for this is the innovative use of your existing email account for communication. Put simply, if you have an email address, you have a Delta Chat address, and can start chatting with other Delta Chat users immediately. Indeed, you can even chat without using Delta Chat, but by simply sending and receiving emails.
So Delta Chat is essentially a contemporary user interface on top of your already existing email infrastructure. There’s not only a desktop client, but also applications for Android and iOS too.
We think Delta Chat is a great way for people to stay in touch using a modern interface, without the modern pitfalls of corporate tracking and centralised control. It’s a brilliant concept executed well. Grab Delta Chat from Flathub now to try it out.
BlockOut II
BlockOut II is a free implementation of the classic 1980’s arcade game.

BlockOut II is free version of the classic 3D block-falling game from the late 1980’s. It was popular in arcades and with home computer conversions of the era. The goal is much the same as Tetris, fill the bottom of a 3D pit with falling blocks, clearing lines to make room.
This version implements three modes – Flat, 3D Mania and Out of Control, each with different pit sizes and block shapes. There’s also a custom mode where the player can make their own pit and block combinations.
The game is fun, addictive and just like Tetris, frustrating when you run out of space and the “wrong” piece comes up next. All in all, a faithful re-implementation of a classic game, which is fun to play, easy to pick up and difficult to master.
However there’s a minor elephant in the room, not with this game, but how it’s delivered.
Unmaintained Flatpaks
At the top of this post we mentioned that these applications/games have a low number of installs per day. The interesting thing about BlockOut II is that it used to have a fair number of downloads each day, but that dropped through early 2020, as shown by the graph on the beta flathub page for this game.

Now, we’re not saying this graph shows a huge drop from thousands a day to nothing, but it’s certainly noticeable. We have a theory why this might be happening. When users install BlockOut II they will be presented with this, on the command line:
Info: org.freedesktop.Platform//19.08 is end-of-life, with reason:
The Freedesktop SDK 19.08 runtime is no longer supported as of September 1, 2021. Please ask your application developer to migrate to a supported version
Info: org.freedesktop.Platform.VAAPI.Intel//19.08 is end-of-life, with reason:
The Freedesktop SDK 19.08 runtime is no longer supported as of September 1, 2021. Please ask your application developer to migrate to a supported version
Info: org.freedesktop.Platform.GL.default//19.08 is end-of-life, with reason:
The Freedesktop SDK 19.08 runtime is no longer supported as of September 1, 2021. Please ask your application developer to migrate to a supported version
These messages are pretty self-explanatory to a nerd, and are labelled “Info”, meaning this isn’t catastrophic, a warning or error. But it’s still a bit alarming to see this wall of text when installing the application. This isn’t something the user can do much about, other than make the executive decision to continue installing despite this warning, or abandon the install.
To us there seems to be a correlation between when the runtimes became unsupported, this message appearing, and a drop-off in installations for this game. This is already reported as an issue against the flatpak packaging for BlockOut II. Indeed it’s the only issue currently open for BlockOut II.
At the time of writing the issue is approaching eight months old. In theory the fix should be straightforward, just update the runtimes (as has previously been done), check it works, and publish the updated application. But nobody, so far, has taken on the task and completed it.
BlockOut II is a simple retro game with limited appeal, and is available elsewhere for download including in traditional desktop Linux native repositories, so isn’t massively adversely affected by this. It is indicative of a potential systemic issue with Flathub though.
How many other applications are built on old, unsupported runtimes? A quick scan of the Flathub repository on GitHub suggests there’s a fair number. These all will spew out the scary informational message shown above, (rightly) dissuading them from being installed.
There are clearly many more packages (~1400 or so) in Flathub than there are developers who maintain them. Many applications are published in Flathub by well-meaning and enthusiastic contributors, and not the original upstream author.
Some of the applications published on Flathub are completely abandoned upstream, but may still be useful to users. As we mentioned on Friday, Flathub can be used to “preserve” applications – such as Kino. However with nobody contributing to them, the motivation for packagers to maintain these low-user flatpaks is typically lower than for high profile, well maintained packages.
All it takes is for a Flathub contributor to change job, have a baby or some other significant life event to mean they no longer have time or inclination to commit to their packages. The packaging is all hosted on the Flathub GitHub organisation though, meaning anyone could potentially pick this work up, but they haven’t.
So it seems to us that the Flathub maintainers need to work on building a pipeline of new contributors, so applications like this, and others, don’t fall behind. Perhaps the Flathub maintainers should highlight these issues as potentially good “first issues” for new contributors to get involved with.
If they don’t then we’re going to see more of these drop-offs in users of packages that packagers have spent valuable time making available.
The future of software packaging for the Linux desktop is bright, but it needs new blood to stop packages from atrophying.