PORTO — Health tech is a booming market, with no shortage of apps available touted as new ways to help people stay in shape and avoid illness. But one noteworthy newcomer from Portugal is notably singular in its focus: keeping users cancer-free.

Meet HAPPY (Health Awareness and Prevention Personalized for You), a free app developed by biologist Nuno Ribeiro and the Institute for Innovation and Health Research (I3S), in the northern city of Porto. Using persuasion techniques, the smartphone app encourages every-day behavior changes by prompting people — one notification at a time — with information about cancer and advice on how to better prevent it.

The app tracks a user's location and, depending on the time of day and other pieces of information such as UV index, sends the person a maximum of one message per day based on the collected data. If the user is at the supermarket, for example, the app might send a reminder to buy fresh fruits and vegetables. If the person is at the beach, HAPPY might recommend sitting in the shade.

Ribeiro believes there are three main factors that make people alter their behavior: motivation, capability and (this is where the app comes in) timely reminders.

"Knowing about the risks [of developing cancer] isn't enough to alter your behavior," Nuno Ribeiro told newspaper Público. "More often than not, people are aware of the risks but either take those risks or ignore them to keep doing things that give them pleasure," he says.

"Some automatic behaviors are deep-rooted within us and are therefore difficult to break because we're not aware of them," Ribeiro adds. "Technology provides a way to make you aware of these behaviors."

In keeping with B. J. Fogg's theories on persuasive technology, HAPPY also grades a user's performance, awarding people a maximum of 150 points if they follow the app's advice. It also allows users to "compete" with their friends.

During the one-month beta test, the app was successful in helping its 32 users reduce their cigarette and alcohol consumption. Ribeiro notes, furthermore, that HAPPY isn't ad-supported. "It's not there to promote anything except health," he says.