Tesco is to expand the services on its Clubcard mobile phone app as it sends out £119m of vouchers in its summer mailing this week.

The Clubcard app, which was launched in February for iPhones, will be extended to Blackberry devices and in a few weeks’ time will be available on Nokia phones. Since it launched on the iPhone, it has been downloaded by half a million customers.

The app, which turns shoppers’ phones into electronic Clubcards, enabling them to scan their phone screen at the till instead of a card, will feature a new service from next week. It will allow shoppers to check their points balance on their phones and use a Clubcard calculator to find out what rewards they can get over a year.

Several retailers have launched apps over recent months, with online grocer Ocado the first to market among the grocers.

This week Argos launched an iPhone app, which provides a click-and-collect service, with 17,000 products available for in-store reservation. It also has a price and stock checker, which is updated in real time.

When Tesco launched its app, it said it expected to attract younger customers, especially men, as its research suggested they were less likely to carry a card.

Tesco has 15.5 million Clubcard users and loyalty schemes have become a key battleground in the grocery sector since late last year. Tesco launched its Double Clubcard campaign, offering double points, and Sainsbury’s launched its coupon-at-till offer - both of which are ongoing.

Asda has steered away from loyalty cards, focusing instead on its Everyday Low Prices pledge.