Best Flatpak Apps to Install on Steam Machine

Start with a browser, ProtonPlus, Heroic Games Launcher, and one media player. That covers the gaps most Steam Machine owners will notice first. Everything else should solve a problem you actually have.

Valve's Desktop Mode FAQ says Discover installs Flatpak applications to the writable part of the drive, where future SteamOS system updates should not break them. It also warns that software installed outside Flatpak, including packages added with pacman, may disappear after an update.

That makes Discover the normal installation path. It does not mean Valve has tested every Flathub application on Steam Machine. This guide checks the current listings and project documentation, but we have not installed every recommendation on a retail Machine.

Why Flatpak fits SteamOS

SteamOS keeps its system image read-only. Flatpaks live separately from that image, so an operating-system replacement does not have to replace the applications with it.

Flatpak also isolates applications from the host by default. The Flatpak permissions documentation explains that applications begin with very limited host access, then gain specific access through package permissions, portals, or user overrides. Those permissions vary. Check the permission summary and publisher-verification label in Discover or on Flathub before installing anything, especially proprietary software distributed by the community.

Install these four first

A browser. Firefox's Flathub package is verified by Mozilla and is the straightforward default. Install Microsoft Edge only when a service requires its documented workflow. For example, Microsoft's Xbox Cloud Gaming instructions use Edge while warning that its SteamOS Flatpak is community maintained and not officially supported by Microsoft.

ProtonPlus. ProtonPlus installs and manages GE-Proton, Wine, DXVK, and related compatibility tools for Steam and other Linux launchers. Our Proton-GE guide explains when a third-party compatibility build is useful and when Valve's Proton should remain the default.

Heroic Games Launcher. Heroic's documentation covers its Epic, GOG, and Amazon Games integrations. It can install Windows games with Wine or Proton, and its Linux quick-start guide explains how to add them to Steam. Each store login and game remains a third-party path. The non-Steam games guide compares Heroic with the other launcher options.

VLC or Haruna. VLC is the broad-format default. Haruna is a KDE media player with configurable shortcuts and playlist controls. Pick one unless you already know why you need both.

Gaming and compatibility

Lutris is a game manager with launcher and emulator integrations. Its current download page includes SteamOS-specific installation and Steam-shortcut guidance. Choose it when you need one of those integrations; otherwise Heroic is the simpler store-focused starting point in this guide.

Bottles organizes Windows applications and games into separate Wine environments. The current Bottles listing documents runner changes, dependency installation, repair, and backup controls. It is most useful for Windows software that is not naturally managed as a Steam game.

ProtonUp-Qt is an alternative compatibility-tool manager. Its project page describes managing Proton-GE for Steam and Wine-GE for Lutris. Choose ProtonPlus or ProtonUp-Qt unless you have a specific reason to keep both managers.

Media and streaming

Jellyfin Desktop is the current name of Jellyfin's desktop client. Its Flathub listing describes hardware decoding, audio passthrough, and playback paths intended to avoid unnecessary transcoding.

Plex HTPC is Plex's television-sized Linux client. The Plex HTPC listing describes a ten-foot interface for a computer connected to a large display. This is the client, not Plex Media Server.

Moonlight is available on Flathub and streams games and desktop applications from another computer. The Moonlight setup guide covers pairing a client with a Sunshine host. It is useful when another PC in the house is faster than the Machine or already holds the game you want to play.

Spotify is available, but the Spotify Flatpak listing labels it as a community-provided package that Spotify does not verify or support. Use the browser instead if that packaging boundary matters to you.

A good family-room app

GCompris is an educational suite for children ages 2 through 10. Its project overview covers reading, arithmetic, science, geography, computer skills, and games. The GCompris 26.0 release notes say that release contained 197 activities.

The current GNU/Linux download is free software. The unlock note on that page applies to an old Windows release, not the current Linux build. The separate GCompris-teachers companion can prepare classroom datasets, but it is not required for normal use. Check individual activities with your controller rather than assuming every one has a gamepad layout.

Utilities worth adding

Flatseal is the first place to look when a Flatpak cannot see a folder or device you expect. Its Flathub listing describes it as a graphical permission editor. Change only the permission blocking the task; broad filesystem access weakens the sandbox you installed Flatpak to get.

Warehouse adds package details, rollback, runtime pinning, Flatpak masking, and cleanup controls beyond Discover's basic install and update flow. The Warehouse listing also documents snapshots of application data and cleanup of data left by removed apps.

Filelight turns disk usage into a visual map. Its Flathub listing says it can scan local, remote, and removable storage, which makes it a useful first check when game installs and desktop applications compete for space.

Do not look for a Flatpak partition editor here. Partitioning and formatting require system-level disk access that does not fit this recommendation list. Use SteamOS's Storage settings for supported game-library media and the Steam Machine storage guide before reaching for a privileged desktop tool.

What to skip

A second app that does the same job. One browser can be the default, one compatibility-tool manager is enough, and one local media player covers most files.

An unverified package you have not inspected. Flathub presence establishes that a package is available, not that the upstream developer built it or that Valve supports it on Steam Machine.

Instructions that begin with pacman for an ordinary desktop app. Check Discover first. If no Flatpak exists, decide whether the application is worth maintaining outside SteamOS's supported update path.

A desktop app for a service that needs to run all day. Flatpak is designed around applications, not every kind of background server. Persistent services need their own update, storage, permission, and startup plan.

Launching an app from Gaming Mode

Valve supports adding desktop applications to the Gaming Mode library. Open Steam in Desktop Mode, choose Add a Non-Steam Game, select the application, and return to Gaming Mode.

The shortcut does not make a mouse-first interface controller-friendly. Set a Steam Input layout with trackpad or stick pointer controls when the application needs them. Media clients and Moonlight are the strongest candidates for Gaming Mode; Flatseal and Warehouse can stay in Desktop Mode.

Keeping the list tidy

Use Discover's Updates view for installed Flatpaks, and remove applications you stopped using instead of carrying every recommendation indefinitely. Warehouse is useful when you need to inspect a package, roll back an update, or clean up its leftover user data.

The useful list is the short one you can still explain six months later: a browser, the gaming tools tied to libraries you own, a player for the media you use, and one or two maintenance utilities.