I just installed this for the first time and it does not do what it says, I have the same issue as another reviewer, there is no "Add to Firefox" button, instead there is just a button that says "Available on Chrome" which if I click redirects me to download Chrome.
I am running Firefox 50.1.0 on Mac OS X in case the operating system matters, but I don't think it should matter for this sort of extension that doesn't interact with anything else on the OS. Anyway I hope you get it fixed soon, I gave 5 stars since someone else reported the issue and you replied and said you'd fix it so I am trusting you to fix it. Thanks.
Edit: a little over a week later, now running Firefox 51.0.1 on the same computer, now it works flawlessly, I have no idea what happened, I did not change any settings. I was not in private mode, but I do have Do Not Track requests turned on. Some of my other extensions may have interfered, I don't know, anyway it appears to work fine now. I just used it to install a signed version of a Chrome extension in Firefox (one called FindFlix) and it works perfectly.
Thank you Rich for this review! We found the problem. Are you using private mode? Or in a new private window? This was causing the issue in my tests. Please see and if you have an account please discuss with me here - https://github.com/Noitidart/Chrome-Store-Foxified/issues/36
Having same problem...  Extensions loads into Firefox  Chrome store add button reads 'Add to Firefox'  Click 'Add to Firefox' button  'Foxified' extension loads in new tab  'Foxified' icon pulsates, message reads...  "Preparing to download and install..."  Nothing happens after that :(
Difficult to install an extension - I have to clear cache and restart browser however I've tried 5 different extensions - all things Firefox doesn't have since it updated to web extensions and none of them work so what good is this? I mean conceptually its a great idea but imo this whole update to web extensions which just turned off a lot of developers has been terrible.