Welcome to Firefox for Android Add-ons.
Add extra features and styles to make Firefox for Android your own.
CloseReview for Profile Buttons by Dan Moorehead | PowerAccess (PowerAccess.net)
Rated 1 out of 5 stars
Button's aren't available to add to App menu or toolbars, at least with Firefox Developer Edition (v55 x64) with e10s Multi-Process enabled. ProfileSwitcher is an alternative that does work, though doesn't have option to open the profile folder and the separate Open Profile Folder extension doesn't work with my configuration.
To create your own collections, you must have a Mozilla Add-ons account.