Developer reply by Tomasz Lewoc
Rated 4 out of 5 stars
I love this app, but when I switched what Google account I was using with it, the app didn't switch, and I'm not sure how to tell it that I switched the account!
I'd love a contact address for this kind of trouble shooting, because I'm sure it's something stupid that I've just forgotten!
Give me a break. You could have found the solution by just scrolling down the first page of reviews or looking around in Thunderbird for a bit.
To switch accounts, go to the add-on's options under Tools -> Add-ons and clear local data and authentication tokens.
To create your own collections, you must have a Mozilla Add-ons account.