Welcome to Firefox for Android Add-ons.
Add extra features and styles to make Firefox for Android your own.
CloseDeveloper reply by Jens-Uwe Groß
Rated 3 out of 5 stars
I often have to hit the empty 'em button 2 or 3 times before it will do what it says. Other than that, it seems to work
Please note that folders related to IMAP accounts are processed asynchronously. This might explain why you perceive the button as not responding.
To create your own collections, you must have a Mozilla Add-ons account.