NOTE: Upstream request now @ https://gitlab.gnome.org/Teams/Engagement/marketing-design/issues/3 (give it a 👍)
It seems unfair that the cool kids like Google Play, F-Droid and Firefox all have snazzy badges for their add-ons, so I decided to make one.
I have asked and been given permission by GNOME licensing to create this badge. It is more directly inspired by F-Droid's badge, with the GNOME logo and fonts taken directly from extensions.gnome.org. Logo and fonts are important when using GNOME trademarks, so please don't distribute changes without obtaining permission from the GNOME Foundation (it's really easy and they're very nice).
I have a rather amateur sense of alignment and design and it's english only. If someone were inclined to take this on as a more official project, F-Droid has some scripts for generating PNGs and internationalised badges in their artwork repository at https://gitlab.com/fdroid/artwork/tree/master/badge that could be adapted.
You're welcome to link the image from here, as long as Github doesn't start complaining. The SVG is in Inkscape format, and the PNG is 646x250px just like Google's.