Bob Mackenzie, father of the BBC's swingometer, would be thrilled. The Conservatives have devised an iPhone app for the election whose main feature is an electronic swingometer.

Tilt the phone up and it moves to the blue corner, showing how many seats the Tories would win for every percentage point gained. Of course, tilt it the other way and it moves to the red corner and seats head to Labour.

George Osborne says the app, which will also work on the iPad, is part of the Tories' digital campaign, which has been devised by the party's internet guru Rishi Saha. "We are going to be issuing a digital call to arms and make this the most online campaign for us," Osborne, the Tories' election campaign director, says.

The app will also allow Tory supporters to follow in the footsteps of Barack Obama's campaign, which energised independent voters by so-called "peer-to-peer persuasion". They will be able to make a campaign call to everyone in their phone book. During the call a sheet pops up, allowing the volunteer to record details of potential voters which are then processed into the party's main telephone database.

Osborne says the key features of the Tories' digital campaign are: launching a "fight the smears" website so supporters can upload Labour leaflets that distort Tory policies; crowdsourcing the Labour manifesto to highlight repeated pledges; and the "MyConservatives" invitation-only intranet site which allows people to carry out telephone canvassing from home in the same way as the iPhone app.