firefox

Set pdf to system handler.

about:config

widget.wayland.fractional-scale.enabled=true

Disable sound:

media.volume_scale=0.0

native apps

Set up a firefox profile named apps without the ui using a custom userChrome.css. Disable restoring tabs on start. Now you can run:

firefox -p apps web.whatsapp.com

to start e.g. Whatsapp. Create a .desktop entry for your app like the one below.

work profile desktop shortcut

.local/share/applications/firefoxwork.desktop

[Desktop Entry]
Version=1.0
Name=Firefox Work
GenericName=Web Browser
Comment=Browse the Web
Exec=firefox -P work
Icon=firefox
Terminal=false
Type=Application
StartupNotify=true
Categories=Network;WebBrowser;
Keywords=web;browser;internet;
Actions=new-window;new-private-window;profile-manager-window;

X-Desktop-File-Install-Version=0.26