Stopped using this app, not worth the time or effort.
The gap in the perspex for the phone to scan is tiny. I could easily see myself clipping the plastic and phone falling from my hand.
And there's also the worry that the damn scanner will not be working after buying everything. I did my shopping, said I wanted to scan and then told it wasn't working. Another worker had to open a till and I scanned it there. Embarrassing holding everyone up for that.