A price worth paying? We'll let you be the judge. The ads, offers and other paid-for content will come from brands such as British Airways, McDonalds, Doritos and Branston. Unlockd has also partnered with Facebook to deliver "relevant and personal" Facebook ads, and the Sun for what it hopes are interesting news stories. Everything can be dismissed by tapping a small cross mark, or, if you're taken by something, you can swipe through to see more information or hit a heart icon to save it for later.

Many will bristle at the notion of choosing to see more ads on their phone. The concept runs counter to other mobile networks, such as Three, which are looking to block mobile ads altogether. Here, of course, the proposition is a little different. Tesco and Unlockd are offering advertisers a prime position on people's phones -- one that would normally be impossible to reach. Whereas customers choose ad-blockers to improve their experience -- usually for free -- here they can degrade it (the occasional ad can be useful, of course) in order to receive some financial gain.