The upcoming Mozilla Firefox 86 update will drop the app mode for websites, which is also known as SSB or Site-Specific browser. It that allows running a page as an app on your computer with a separate icon on a taskbar, in a dedicated window that will appear in the app list.
The reason behind the feature removal is that developers found “little to no perceived user benefit” to this feature, and “multiple known bugs” hinder further development. Thus Mozilla has no plans to develop SSB any longer but it will keep supporting progressive web apps on Android.
If you want to try SSB while it is still available, do the following:
- Go to about:config page and look for the browser.ssb.enabled flag.
- Change its value to true and restart the browser.
After that, open any page and click the three-dots button in the address bar and click on the Use this site in App Mode button. Alternatively, it can be started from the command line, like this: firefox --ssb Winaero - At the edge of tweaking.