One in five smartphone owners use apps on their handset to complete some of their shopping, says the BIO Agency.

According to the marketing firm, Brits spend £581m a year through apps, with each smartphone owner spending an average of £30 per month. Groceries, DVDs and cinema and train tickets are the most commonly purchased items.

"It's about convenience and simplicity when purchasing. You might not have access to a computer but you do have your phone with you," said the managing director of the BIO Agency, Peter Veash.

"You can also compare prices easily. You can be in shop A and instantly check the price in shop B."

See also: How to download and install apps on an Android device