SAN FRANCISCO—Calmwell, a mindfulness app that launched last month to enthusiastic reviews from people who have not yet turned off its notifications, confirmed Tuesday that its core feature is working exactly as designed: the more stressed a user reports feeling, the more often the app reaches out to check in on them.

“When someone tells us they’re at an 8 out of 10 on the overwhelm scale, we hear that,” said co-founder Brandt Ellisworth-Pryce, speaking from a standing desk he described as “a boundary.” “And we respond the way a good friend would: by tapping them on the shoulder again, and again, and again, until they feel held.”

The app, which the founders call “deeply empathetic technology,” asks users to rate their stress several times a day. A rating of 1 to 3 earns a single gentle chime. A rating of 7 or above activates what internal documents call Compassion Surge, in which users receive a notification roughly every ninety seconds reading things like “Pause. Breathe. You’ve got this,” and “Hey, just checking in on your checking in.”

Users who respond to a notification by saying they feel worse are escalated to Tier Three, which adds haptic vibration and a message that reads, “We noticed you’re struggling. Let’s talk about it.” Users who dismiss that message are sent a follow-up asking whether they’re avoiding their feelings.

Dr. Odalys Venkataraghavan-Moore, a senior fellow in Applied Reassurance Logistics at the Institute for Anxiety Throughput in Boise, said the approach is consistent with a long tradition of solving problems by adding more of them. “Historically, the most overwhelmed person in any room is also the one with the most unread messages,” she said. “Calmwell simply closes the loop.”

Early results have been mixed. In a pilot group of 400 users, 94 percent reported feeling “acknowledged,” while 100 percent reported being unable to finish a sentence. One beta tester said she had been guided through a breathing exercise so many times in a single afternoon that she now exhales involuntarily during meetings.

“It sent me a reminder to take a break from my phone. Then it sent another one to ask how my break from my phone was going.”

That was the account of Marcus Telfer, 34, a beta user who said he has not experienced a quiet moment since March. Telfer added that he tried to uninstall the app but was met with a screen asking whether he was sure he wanted to give up on his wellness journey, followed by 11 more screens.

Calmwell has responded to the criticism with a new feature, Calmwell Calm, which sends users a notification when they have received too many notifications. The notification links to a guided meditation, which sends its own notification when it ends.

Ellisworth-Pryce said the company is already working on a premium tier that would allow users to reduce their notifications for $14.99 a month. “We think of it as self-care,” he said. “Which, to be clear, we will be reminding you to do.”

At press time, Calmwell’s own servers were reportedly experiencing severe stress and had sent the engineering team 6,200 messages encouraging them to take a moment for themselves.