"Smartphone addiction does harm your teen's mental health", "Six ways social media negatively affects your mental health" and "Man murders wife over her social media addiction".

These are just some of the weird and varied online headlines I spotted that highlight the dangers of technology addiction but there's at least one app that claims to be good for you.

Happiness chatbot app Wysa is a global success story after coming through the Facebook Start-up accelerator and has clocked up more than 300,000 users across the world.

But the app, which uses AI to converse with users and improve their wellbeing, very nearly never happened at all.

London-based software company Touchkin had devised a way to detect depression using basic smartphone sensor technology. CEO Jo Aggarwal, who had suffered from depression herself, decided that the best way to get people to use the technology was through a simple accompanying chatbot.

Initial research showed that they could identify the early symptoms of depression with 90 per cent success rate. However Aggarwal suddenly saw a problem with the business.

“Our technology was just going to create a wave of [people who would be prescribed] anti-depressants,” she told BusinessCloud. “That is not what we started out to do!”

She and her co-founders decided that promoting good mental health practice was more impactful than simply identifying the symptoms of poor mental health.

“It doesn't matter if someone is suffering from depression and moving in a certain way,” she said. “All of that movement detection went out of the window.”

The Wysa app, which converses with users by analysing their text through AI, became the company’s sole focus. It has 50 separate ‘models’ to approach people suffering from a variety of problems in the most appropriate way – from depression to less serious situations such as low self-esteem.

Aggarwal says people found that the chatbot combined the relief of talking with the comfort of anonymity.

“Sometimes you have to vent a little bit before you can be mindful,” she explained. “We have had people write to us and say it has changed their lives and that's personally very satisfying for us.”

Aggarwal estimates that the company adds another 500 conversations to the app every month, with almost 4,000 at present. Last year it raised $1.3 million in seed funding and now employs a range of talent capable of fine-tuning the AI.

These include therapists, people who structure the content and dialogue writers who then humanise it. The company has even brought in movie scriptwriters to ensure that the replies sound as natural and human as possible.

Amazingly the app’s 300,000 users were acquired through reputation alone.

"We haven't spent a penny on advertising. We've let Wysa find its own market through people talking about it on Twitter and journalists hearing about us," said Aggarwal.

The app is free to use but the company now creates revenue from its premium ‘coach service’, which provides access to a human coach, as well as from research grants.