Hi steveuk,

You rated 3 stars and said doesnt work. Do not use this review page as a support forum. I am happy to help you at https://www.stefanvd.net/support

“Doesnt work” do not provide much information what does not work. Do you see not the Z icon in the Firefox toolbar? Or do you see not the content inside the zoom popup panel? Or will it zoom not in/out on that certain website?
Please check if you are using the latest AndroidOS. And that you are using the latest Firefox web browser version.

For further help, please use the email support at https://www.stefanvd.net/support

Thanks,