@dangillmor use the Install App function on mostly any browser which creates a 'bookmark' that will open a dedicated browser for the application.
https://help.vivaldi.com/desktop/miscellaneous/progressive-web-apps/
this works for most Android browsers.
Note: I avoid installing 'native' applications when it does not offer any additional functionality; such as offline support. Eg. mastodon needs an active connection to be useful.
@gbraad @dangillmor
maybe you didn't get it... that's his whole point!
But many services do not have a dedicated web app, so you cannot use it on a phone.