Deliveroo’s Will Shu owes all his success to a small gang of grannies from Gateshead. Well, not quite, but the pioneering pensioners were the first on the planet to order food via a screen, and have claim to the genesis of the delivery apps we have today.

The grannies were part of ‘The Gateshead Shopping Experiment’, in which they ordered goods from three retailers in the town: Tesco, Lloyds Pharmacy and Greggs. This was via Videotex, an advanced version of Ceefax and Teletext that allowed for two-way communication.

The experiment was recounted in series The Secret Genius of Modern Life (BBC Two, 17 November, 8pm) – this week on food delivery apps – with hugely likeable host Hannah Fry trying the ordering system herself. “A retro delight,” she said – shocked at the 20p cost of a sausage roll.

Fry scrutinised each element of the apps – from the algorithms that present ‘suggested for you’ home screens, the maths behind estimated delivery times, to the satellites that navigate riders.

Each innovation’s long history was not ignored. From Sputnik to Tim Berners-Lee. “It’s not that the innovation happens in isolation, it’s that everything comes together at the same time,” Fry said.

There were some fun tales. The inventors of a early Pizza Hut internet ordering system recalled: “We actually got questions: does the pizza come out of the floppy drive?”

As Shu put it: “It’s pretty easy to conceptualise but what’s behind it is very complex.” Fry did a grand job of guiding viewers through.