Radiohead have updated PolyFauna, their seven-month-old tablet and smartphone app, with an array of new visuals and atmospheric sounds. The surprise upgrade means that PolyFauna is no longer just a companion to 2011’s The King of Limbs: it has its own original music, including unreleased vocals by Thom Yorke.

Yorke began teasing the Polyfauna update toward the end of August, tweeting images and sketches for the app. More drawings and paintings have also appeared at What Have You Done To My Face, his Tumblr with artist Stanley Donwood.

The brainchild of Radiohead, Donwood, producer Nigel Godrich and the developers at Universal Everything, PolyFauna has been described as an “immersive, expansive world of primitive life, weather, sunsets, mountains and forests”. It was inspired by “early computer life-experiments and the imagined creatures of our subconscious”, allowing users to explore a mysterious, expressionistic world while listening to Radiohead’s spooky soundtrack.

The PolyFauna update marks Radiohead’s first musical release in about three years. While most of the band members have been busy with various side projects, from Jonny Greenwood’s movie scores to Yorke’s Atoms for Peace and Phil Selway’s forthcoming album, the group are reportedly planning to go back into the studio this month. “We’re going to start up in September, playing, rehearsing and recording and see how it’s sounding,” Greenwood told BBC 6 Music in July. Earlier this spring, Greenwood referred to the Oxford group as “a slow-moving animal”.