Used to be a 5 / 5 extension, then after the v3 fiasco with Chrome, got updated for parity with the Chrome Exctension. It lost essentially all that made it worth using, just for it to be useless the same way in two browsers now.

Also appears to be entirely abandoned by the developer.

A real pity, it used to be an extension that I considered worth it to be included natively in Firefox

Ever since version 2 it doesn't open images in BetterViewer by default. And that's highly annoying as it was the only reason why I used it so extensively compared to other similar extensions. If I now forget to go all the way down in context menu after right click and instead of "open image in new tab" I don't click "Open image in betterviewer" I have to do additional steps of clicking again and choosing it.

Don't know if this is Mozilla's reason or not, but it makes me want to use this extension less and remove it, as it's then easier to just screenshot images via other apps in my PC and/or open them in that editor and it'll be same amount of clicks.