NOT many people seem to know this, but Coventry has had three cathedrals. The current cathedral was built in the 1950s to replace the second cathedral, which had been destroyed by the Luftwaffe in 1940. That building was a replacement for the 11th-century St Mary’s Priory and Cathedral, which was demolished on the orders of Henry VIII.

Now, thanks to modern technology, visitors to the site can see for themselves what the second cathedral looked like before it was gutted in the Coventry Blitz.

The app Rising Ruins uses a form of augmented reality to show users what they would have seen if they were standing there before 1940. Augmented reality is the same technology used in the Pokémon Go games (App Guide, 19 August). But, rather than superimposing an image on top of the camera image, it replaces it completely.

The app is built on Google Tango, a new platform for Android devices which combines the Global Positioning System (GPS), to determine where you are, with other systems, to determine your orientation and movement.

Google says that its Tango platform can produce data in “six degrees of freedom”. I have no idea what that means; but what it produces is a stunning app that allows you to lift your tablet, or phone, up to the ruin’s windows and see the stained glass that no longer exists. The original altar, doors, tiled floor, and other features of the cathedral have been digitally recreated for the app.

Members of the public were given the opportunity to try out the app earlier this week during the Rising Global Peace Forum, which took place in the modern cathedral building.

A similar app will be available next year for Lincoln Cathedral. Lincoln is one of 12 cities chosen by VisitEngland to receive a grant from the Discover England Fund to develop an augmented-reality tourist app. Lincoln’s tourist agency, Visit Lincoln, has formed a partnership with the cathedral for its part of the England-wide project.

A spokesman for the cathedral authorities said that they were the process of selecting a technology company to design the app, which should be released within the next six months. Once published, the 12 new apps will be made available through online travel agencies, trade partners, app stores, and direct to consumers who book breaks in any of the selected cities.

The Lincoln Cathedral app will focus on its absent spires. The first central spire lasted only two years before it collapsed under its own weight in 1237. When it was rebuilt in 1311, Lincoln Cathedral became the tallest building in the world, at 525 feet high, before it, too, collapsed in 1548 through a combination of its weight and storm damage. Two smaller towers were removed in 1807.

“Through augmented reality, we hope to be able use the cutting-edge technology of today to recreate what was cutting-edge in 14th-century Lincoln, and in doing so stimulate interest in what was a fascinating and eventful period in the history of the cathedral’s construction,” the Chapter Clerk, Jackie Croft, said.