So on Starling and Monzo you can integrate with Flux, which can allow you to have paperless receipts (with some stores!)
I think partnering and then integrating this into Dozens would be a great idea as it would help customers see how they spend their money, to the item. This could help them cut down on spending!
Naturally all of this assumes that Flux becomes more widespread, but I believe it will be as Starling and Monzo have integrated while Barclays is also forming a partnership with them. Mixed into this KFC also supports Flux, so I can see others following!