I have seen the future of grocery shopping, and it is in a large supermarket.

Graham Ruddick

That may sound surprising given how much the large grocery store has been written off - or should that be ‘written down’, given the huge impairment charges that Tesco and the major supermarket groups have booked on their assets.

However, the large supermarket still has a key place in the grocery industry, despite the rise of the discounters, convenience stores and online shopping.

The future is a smartphone app Sainsbury’s is developing for its shopper, not for buying groceries online, but buying them in the supermarket.

It is designed to make shopping in a supermarket easier. Customers can write a list of the products they want to buy on the app and it will tell them where in the Sainsbury’s store to pick them up using a map. Shoppers can also search for products while they are actually in the store and the app will still tell them where to go.

When they arrive at the product, the shopper can scan it using their phone. At the end of the shop, the consumer pays for their products by taking a photo of their debit or credit card with their phone. Simple.

The app is being trialled among Sainsbury’s staff in selected stores, but the plan is to roll it out to customers in the next few months.

The app is just one example of how the major supermarket groups are trying to revitalise their large stores across the UK and remind shoppers of just how convenient they are.

The large store, or the hypermarket, has been portrayed as supermarkets’ equivalent of what subprime lending was to the banks during the financial crisis. The leading retailers were greedy and built too many - now they are paying the price.

Tesco is suffering the most, analysts have said, because it has far more stores above 50,000 sq ft than its rivals. It is true that Tesco built too much space. Between its market share peaking in 2007 and today, Tesco built enough new space to match the size of Morrisons’ entire portfolio, yet its market share has declined.

But it is what you do with this space that really counts. Tesco’s problems stem from the mistakes it made with the space - having more supermarkets than its rivals simply meant the problem was exacerbated.

After all, more than three-quarters of grocery shopping is still done in supermarkets. There is also a strong argument that they are the most convenient form of shopping. Where else can a consumer buy all their food for the week - as well as clothing and homeware - in an hour?

The issue is that major retailers became complacent and seemed to think that just plonking a new store down would be enough to attract consumers. They forgot why the self-service supermarket ousted the corner shop as the dominant grocery shopping space in the 1950s.

The big four are now trying to correct their errors and evolve the large store for the modern era.

As well as trialling its app, Sainsbury’s has also overhauled its pricing. For instance, it has scrapped a three-for-£10 offer on its core meats such as chicken and mince. Instead, it has cut the price per pack to £3.50.

The three-for-£10 offer said to shoppers they would only get value if they bought in bulk. But, in an era when shoppers watch what they spend, are wary of waste and often do not know what they want for dinner that day until late afternoon, it has alienated many consumers who instead head to discounters or convenience stores.

This is symptomatic of the mentality that has left supermarkets mired in chaos. Another example was Tesco using its prime slots on the shelf-ends of aisles to get extra income from suppliers, rather than thinking about what the shopper might want to see there.

However, these are mistakes that can and are being rectified by a new generation of bosses. The supermarket is still the heart of Britain’s grocery industry, but it might start to look different.

Graham Ruddick is deputy business editor (retail and technology) at The Telegraph