Ustwo had a big hit with mobile game Monument Valley, but now the company is moving into a new apps area: mental health and wellbeing.

The UK-based studio is releasing an app called Moodnotes for people to track their moods and develop “healthier thinking habits”, as part of a joint venture with US developer Thriveport.

The £2.99 app, released initially for iPhone, is based on cognitive behavioural therapy (CBT) principles, with its developers hoping it will appeal beyond people diagnosed with depression and similar conditions.

“One of our primary goals is to go beyond the clinical sphere, and not just limit this to people who’ve been diagnosed with a mental health problem or difficulty. We know that the wisdom of the field has relevance to every-day life,” Thriveport co-founder Dr. Edrick Dorian told the Guardian ahead of the app’s launch.

“By combining the expert psychological content with the premium design and engaging, enjoyable interface that Ustwo brings, we are hoping to change the face not just of CBT, but also the relevance of psychology – and even clinical psychology – for every-day life.”

Moodnotes works by getting people to regularly log their moods by swiping an on-screen face – on their iPhone or, if they have one, their Apple Watch – between seven stages of happiness, and optionally adding notes about how and why they are feeling that way.

The app will then try to identify patterns in their moods, prompt them with questions to help them understand those feelings, and suggest CBT tactics for identifying and avoiding “thinking traps” that may lead them into a slump.

“We wanted it to be simple but not patronising, intelligent but not academic, and personal but not over-familiar,” said Alana Wood, studio design lead at Ustwo.

“We also realised that it was key that we have some science behind this, and really meaningful content. A lot of brain training apps have come out with no credibility and no experts involved in the design process.”

Moodnotes is the second example of Ustwo blending its design experience with external expertise in a joint venture, following music ticketing app Dice, which launched in 2014.

Dorian and his Thriveport co-founder Dr. Drew Erhardt are both clinical psychologists – Erhardt is also professor of psychology at Pepperdine University – and drew on that experience for a previous app called MoodKit, which was first released in 2011.

“It’s common to have people in therapy track their moods and behaviour, but in traditional psychotherapy getting people to adhere to that using paper journals has been understandably challenging,” said Erhardt.

“The idea that you can incorporate these tools and methods into the one device that we typically have with us almost 100% of the time is very exciting, including the ability to have the device remind you to do a quick mood-rating, which really improves people’s ability to stick to that kind of self-monitoring.”

Moodnotes users will be able to export their data as CSV or PDF files to share with their doctor or therapist, but both Ustwo and Thriveport are stressing that all this data will otherwise remain on the device, for privacy purposes.

“Edrick and Drew were both adamant about how important it was that we keep the integrity of the data, and keep it private. We are very respectful of the fact that this is a very personal application, and not like your typical [physical] fitness tracking quantified-self app,” said Wood.

“Nothing is stored in the cloud, it is completely stored on your device. We would only add features to integrate it into the cloud if that was what customers wanted.”

Wood added that Moodnotes is not part of “the happiness industry” – a burgeoning sector of the apps market – in terms of any promise to make its users happier over time.

“There are a lot of happiness apps out there, and we have specifically steered away from that. It’s important to recognise that positive and negative emotions are part of our lives: we didn’t want people to think that the goal is to be happy all the time,” she said.

“That would be quite unnatural! It’s important that we recognise and celebrate that you have negative emotions as well as positive ones, even if we are providing some help in breaking the cycle that you might be in if you’re mulling over something too much, or thinking negatively.”

Moodnotes is a business in terms of the app being sold for £2.99 upfront, but both Ustwo and Thriveport have other motivations for the joint venture.

As a company, Ustwo wants to work more in the healthcare sector, and Moodnotes will be a showcase for the studio that could bring in more projects for its division that focused on work for clients.

(In fairness, Ustwo’s business director Nicki Sprinz stressed the project’s more personal roots: a group of employees started work on what became Moodnotes as one of their “downtime” projects. “We talk a lot about emotional health at Ustwo: we’re quite a touchy-feely studio!” added Wood.)

Dorian and Erhardt, meanwhile, hope that by spreading CBT principles to a wider audience, far from persuading people to ditch traditional therapy in favour of an app, it may encourage more people to seek out professionals.

“The fear that these mobile devices are aiming to, or have the potential to replace therapy sometimes leads certain mental health professionals to be loath to adopt them, or be prejudiced against them,” said Erhardt.

“We are making a clear disclaimer in the app that this is not a replacement for therapy. It would be foolhardy to expect an app to provide the depth and nuance that are part of therapy.”

Erhardt suggested that only 20%-30% of the people who could benefit from psychotherapy actually receive it, and hopes that apps like Moodnotes can appeal to a proportion of the 70%-80% who do not.

“If we can expose this content to people who wouldn’t normally encounter it because they aren’t having contact with mental-health professionals or even resources, we think there is potential to draw even more interest in obtaining those professional resources,” added Dorian.

“By interacting with and enjoying that content, and understanding the value of CBT or psychology, people may wonder ‘What else can I learn? What else can this field offer me? And theoretically that could draw more interest in obtaining professional services.”

One devil’s advocate question: smartphones can have a negative impact on your mental wellbeing – think notifications raining in throughout the day, or being so addicted that you end up cycling between your inbox and social networks on the toilet or in bed – so by encouraging people to log moods in an app, is Moodnotes possibly part of the problem?

“It’s definitely something we considered, but while other apps are competing for your attention, this is quite different: it’s really about growing your emotional intelligence and self-awareness, and giving time back to people,” said Wood.

“We did a lot of thinking about how we wanted notifications to behave, for example, to avoid adding to that stress. People can customise how often they want notifications, based on when they’d like to be reminded to log.”

“The short answer is that these [smartphones] are tools, and much like any tool in life, they need to be used responsibly. Do we feel like we’re contributing to the problem by developing apps? Absolutely not,” said Dorian.

“If anything, if mobile devices are to be used, it’s nice that they can be used in ways that are empowering and contribute towards people’s health.”