Welcome to Firefox for Android Add-ons.
Add extra features and styles to make Firefox for Android your own.
CloseReview for Dictionary Switcher for Thunderbird by Peter Hendricks
Rated 4 out of 5 stars
Works as advertised, although I've only tested it briefly. I do want to point out that you do need to set the hidden property mentioned in the description for the automatic switching to work. Why is this not set as default?
To create your own collections, you must have a Mozilla Add-ons account.