"Evi has a huge base of the world's knowledge in a form that she can understand and reason with," says Evi's inventor, William Tunstall-Pedoe, who claims that the app can process almost one billion facts. "She uses this knowledge to understand users and answer questions."
That knowledge includes common sense about the world that was previously limited to human beings. "We have developed unique and deep technology that nobody else has and are the leaders in this kind of problem."
In the near future it's entirely possible that artificially intelligent systems like Watson will be integrated into voice-controlled apps like Evi and Siri.
Does Google have a Watson?
No, but a cloud-based Watson able to analyse search terms to find the best answers sounds suspiciously like the world's most popular search engine - and the reality is that Google already has artificially intelligent computers on its radar, too.
Earlier this year Google revealed that its Google X lab had built a nine-layer neural network that could detect faces. Using 16,000 computer cores over three days the model managed to detect faces in among 10 million random images on YouTube, despite not being told there were any faces, and even identified cat's faces and human bodies.
In short, the software learned what a face was, and how to differentiate between human and cat. The final use for this kind of AI isn't clear, but the automation it offers for search seems the most appropriate for Google, whose search engine works on AI - and has done for years.
Is artificial intelligence the next commodity?
"It is certainly going to be a commodity, one available on mobiles and on all computer terminals," says Cochrane, "and it may well be the most vital of all the commodities, surpassing water, food, heat and light. Without it, we will certainly not survive as a species."
Now that's some commodity, though Furber thinks it's all about selling simple 'common sense', with the likes of Siri and Evi leading the way. "They are a bit primitive right now, but I sense that Apple has decided that it is going to make Siri work really well - it'll just take a bit of time," says Furber. "Watson shows what is possible."