Let me explain: When trying to create homescreen shortcuts to URLs, some sites only give you the option to "install" as a progressive web app and remove the normal (and sane) option to merely "Add to home screen." This has annoyed me for so long because, on top of this, there's no way to rename app shortcuts in Android, so for a long time I haven't created a shortcut to my skiff email inbox because it would automatically name itself "react-client," which is aggravatingly obscure.

Just now, it suddenly occurred to me that if I totally disconnect from internet and enter the URL, then Firefox won't know that it's a site that can be used as a progressive web app. taps forehead

Sure enough, I now have a tidy little link called (smartly) "Skiff Mail."

Thought this information might be helpful to someone. Hope you all have a Mozillarific day!