Is my favorite on Chrome, so glad to see it on Firefox. (A major bug was fixed.)

All is well until I cleared the browser cache: all the settings of the add-on also wiped.

Appreciate if you can fix it as I love this add-on. Also it seems, add an engine via CTRL+ALT + click is not working too.

As I've used the Chrome version of this extension on the odd occasions I use Chrome, seeing that a Firefox version has now been released I thought I should give it a try to compare with the other Firefox extension I've been using for years for this functionality. Exporting my settings from the Chrome version to this new Firefox one worked perfectly ... once I'd worked out the not entirely obvious way 'saving' and 'loading' settings work. (I was expecting to save a settings file, rather than click a button to produce a raft of strange text to then copy and then paste into a text file for backup or paste into the field in the Firefox version settings. Unusual, and I think a function to save a file with the settings should be considered.) And the extension has worked perfectly so far. And as compared with the other Firefox extension I had been using, I like that this extension allows folders in the popup rather than having to have all buttons at the top level.

I'm taking off a star, though, for something that makes configuring aspects of the extension not very user friendly for an average user, and that is the way CSS has to be used for basic popup layout, which isn't great for people like me who don't know how to write CSS. I appreciate that it makes the popup layout very, very open to all sorts of customization. But e.g. for me to get a popup with the icons in a grid 4 columns wide, I had to actually ask in the support part of the Chrome extension store for this extension. And while the extension creator responded very promptly with the CSS I needed to copy into the appropriate part of the extension configuration, I think a lot of potential users would just give up and go for another extension (like the Firefox one I was using before) where there are obvious settings for number of columns, padding etc.