Meanwhile, the 25 biggest holders are going to be rewarded with ... return it to your nearest store for a refund," the FSA says. No other products are affected by this issue, Morrisons has said.

The app has already had more than half a million downloads on the Google Playstore, and is 65th on the UK App Store. It has 4.9 stars on Apple, with one user praising its "great deals and smooth ...