When Google paid $3.2bn (£2.1bn) to buy Tony Fadell’s start-up Nest in 2014, it got much more than just an internet-connected thermostat and smoke detector.

It got the man dubbed the “the iPod’s father” – the engineer/designer who sold Steve Jobs on his vision of a portable music player, and then worked to build it, update it and then repeat the process with the iPhone.

In January, Google’s troubled Glass computer was added to his list of duties.

“It wasn’t handed to me and said, ‘Tony clean it up,'” Mr Fadell clarifies, “I offered.”

“I remember what it was like when we did the iPod and the iPhone. I think this can be that important, but it’s going to take time to get it right.”

Read more: Will Tony Fadell eclipse his ex-workmate Jony Ive?