As the wellness movement surges, the concept of self-care is increasingly in vogue, and app developers are rushing to make the most of it. Calm, Happify, Talkspace, Pacifica, Shine, Gratitude and Lantern are just a few of the self-care-driven apps populating the iOs and Android app stores right now, and they’re not just taking up space.

In the first quarter of 2018, the top 10 self-care apps in the U.S. earned $15 million in revenue in the States and $27 million worldwide, according to research from the market intelligence firm Sensor Tower. Those same apps made about 170 percent more revenue worldwide in the first quarter of 2018 than last year’s top 10 did during the same period.

“I think everyone would agree we live in a world that is incredibly fast-paced,” said Tiffany Sun, the head of content and strategy at Happify, which provides users with activities and games meant to help them overcome stress and anxiety. “We’re in this constantly frenzied state, and I think that’s why people are realizing they need to slow down a bit and be mindful of what they’re doing.”

Carla White can certainly relate.

In 2005, she was living in London and working for Microsoft when she decided to exit the company to launch her own wireless network business. Trying to get it off the ground was more stressful than she expected.

“I wasn’t sleeping as much; I was binge-watching TV, drinking, gaining weight and just in denial about what was going on,” she said.

As the stress continued to build, her father passed away, pushing her further into the throes of depression. A Hail Mary move back to the States and a subsequent struggle with double pneumonia left White willing to do anything to feel better, so she took the advice of a talk-show host and began writing down three things she was grateful for each day.

Pleased with the results — “it turned my life around,” she said — White launched the Gratitude app in 2008. Using gamification, the app encourages users to write about what they’re grateful for 30 days alongside any images from the day that are relevant. It also spontaneously shows users past gratitude moments from the past year as pleasant reminders.

“Nobody knew what gratitude journals or apps were [back then],” she said. “Now it’s a hot buzzword.”

Indeed, today there are hundreds of gratitude-related apps available to consumers, and most broader wellness apps — including Pacifica and Happify — include a thought-recording component similar to Gratitude’s.

Other common tools include goal setting, guided learning of new coping skills, peer support communities and audio meditation sessions. The bulk of them are inspired by both the popular psychology movement and cognitive behavioral therapy, a form of psychotherapy meant to treat problems and boost happiness by modifying “dysfunctional” emotions, behaviors and thoughts.

One of Happify’s most popular elements, according to Sun, is its “Uplift” game, in which users tap on positive affirmation balloons and ignore the negative ones. “They’re addicted to it like they might be any other game, but it’s doing real good in their lives,” she said. One user, for example, reported that “Uplift” helped her get through a severe bout of depression, when she couldn’t bring herself to do any of the more in-depth activities on offer.

While many of these apps cater largely to people with diagnosed depression and/or anxiety, they’re all casting a wider net and positioning themselves as helpful for everyone.

“The tools are really great for anyone as mental hygiene and a way to stay in touch with yourselves,” said Ashley Toy, the head of marketing at Pacifica, a self-care app that has been around for a little over three years and reports 2 million users. “A lot of people who use the app hadn’t really thought about monitoring their mood before, but now realize how much of an impact it can have.”

As for what’s driving this trend, most people point to the millennial affinity for self-care and wellness: In 2015, the Pew Research Center found that more millennials reported making personal improvement commitments than any generation before them, spending twice as much on self-care essentials like workout regimens and life coaching.

But today, Americans on the whole are ripe for it: A recent Gallup study found that Americans’ well-being declined in 2017 after trending upward for three years. Minorities, low-income families, women and Democrats were said to bear the brunt of this decline, hinting that it’s at least partially political.

“Self-care is more important now than ever,” said Marah Lidey, the co-founder of Shine, a motivational app and text messaging experience, which just closed on $5 million in Series A funding led by Comcast Ventures, bringing its total funding to over $8 million. Unsurprisingly, 91 percent of Shine’s over 2 million users agree, with 91 percent of them reporting that self-care is more important than it was two years ago.

Also contributing to the rise of these apps is a decreasing stigma around mental health issues. Celebrities from Selena Gomez to Michelle Williams have spoken openly in recent years about their personal struggles with depression and anxiety, with athletes like Michael Phelps following suit. Some, including Gabrielle Union and Kelly Clarkson, have put their support behind these self-care apps as well.

“It’s empowered people to be open themselves and seek the treatment and help that they need,” said Toy.