What's going on with this add-on? Most of the (Android) barcode scanning apps I try simply cannot scan the codes that Tab2QR generates. I've tried QR Code Reader from Scan (a really good one, IMO), QR Droid, i-nigma, and Barcode Scanner from ZXing Team. Only the latter of those considers them valid. The others just stare at them endlessly. Maybe I just have a bad selection of apps, but QR codes from other sources usually work just fine.
"Offline QR Code Generator" by rugk does the same thing without requiring permission to access all browser tabs. Don't know why this add-on needs it when obviously it only needs the current tab URL to make a QR code.