Tate has released an iPhone app to accompany Miroslaw Balka's 'How it Is' installation in the Turbine Hall at Tate Modern.
The app incorporates the Polish artist's own handwritten notes, playlists and interviews about his Turbine Hall commission and allows users to immerse themselves in a dark and mysterious 3D world.
How It Is – unveiled last October – invites the visitor to step into a 30-metre long pitch-black chamber which resembles a giant shipping container.
The app uses the iPhone's built-in GPS receiver to unlock a secret game if the program is used by real-world visitors to the Turbine Hall.
• How It Is is in the Turbine Hall until 5 April.