Best Flatpak Apps to Install on Steam Machine

Start with a browser, ProtonPlus, Heroic Games Launcher, and one media player. Add other apps only when they solve a specific problem.

Valve's Desktop Mode FAQ recommends Discover because Flatpaks live on writable storage and should survive SteamOS system updates. Packages installed with pacman may not. Valve has not tested every Flathub app on Steam Machine, and we have not tested every recommendation on retail hardware.

Flatpaks are sandboxed, so file and device access varies by app. Check the publisher, verification label, and permissions before installing. The Flatpak permissions guide explains how that access works.

Install these four first

A browser. Firefox is verified by Mozilla and is the simplest default. Install Edge only for a service that requires it. Microsoft's Xbox Cloud Gaming instructions use Edge but note that its SteamOS Flatpak is community maintained and unsupported by Microsoft.

ProtonPlus. ProtonPlus manages GE-Proton, Wine, DXVK, and related tools. Use our Proton-GE guide before replacing Valve's default Proton.

Heroic Games Launcher. Heroic supports Epic, GOG, and Amazon Games. Its Linux quick start covers adding installed games to Steam. Store logins and compatibility remain third-party paths; our non-Steam games guide covers the tradeoffs.

VLC or Haruna. VLC is the broad-format default. Haruna is a KDE alternative with configurable shortcuts and playlists. Pick one.

Add these when needed

Gaming and compatibility

Lutris combines launchers and emulators. Its download guide includes SteamOS installation and Steam shortcuts. Use it when Heroic's store-focused approach is too narrow.

Bottles keeps Windows apps in separate Wine environments. Its Flathub listing covers runners, dependencies, repair, and backups. It fits Windows software that is not managed as a Steam game.

ProtonUp-Qt is an alternative manager for Proton-GE and Wine-GE. Choose it or ProtonPlus, not both.

Media and streaming

Jellyfin Desktop is the current desktop client. Its Flathub listing documents hardware decoding, audio passthrough, and direct playback.

Plex HTPC provides Plex's TV-sized Linux client. It is not Plex Media Server.

Moonlight streams from another computer. Follow its setup guide to pair it with a Sunshine host.

Spotify is available, but its Flatpak is community packaged and unsupported by Spotify. Use the browser if that matters to you.

Family use

GCompris offers activities for children ages 2–10 across reading, math, science, geography, and computer skills. Version 26.0 includes 197 activities, and the current Linux build is free. Controller support varies by activity.

Utilities

Flatseal is a graphical permission editor. Use it when an app cannot reach a needed folder or device, and grant only the missing access.

Warehouse adds rollback, runtime pinning, snapshots, and cleanup beyond Discover's basic controls.

Filelight maps disk usage across local, remote, and removable storage.

Partitioning needs system-level access, not a Flatpak. Start with SteamOS Storage settings and the storage guide.

What to skip

• Duplicate browsers, compatibility managers, or media players.
• Unverified packages whose publisher and permissions you have not checked.
• pacman instructions for ordinary desktop apps. Check Discover first.
• Desktop apps used as always-on servers. Persistent services need a separate plan for startup, updates, storage, and permissions.

Launching an app from Gaming Mode

In Desktop Mode, open Steam, choose Add a Non-Steam Game, select the app, and return to Gaming Mode. Mouse-first apps still need an appropriate Steam Input layout. Media clients and Moonlight fit here better than maintenance tools.

Use Discover to update Flatpaks and remove apps you no longer use.