The short version

What it is: a breathing app for iPhone and Android from an Israeli startup. You follow a pacer for a few minutes while, FlowMD says, the phone reads your pulse through your fingertip on the camera and your breathing from your belly's movement.
Price: subscription required: $6.99 a week, $7.99 a month, or yearly plans listed from $14.99 to $59.99 on the US App Store (as of October 2026).
Best for: people who want quick sessions with some feedback and don't want to buy a sensor.
Skip it if: tracking makes you anxious, you have an irregular heartbeat, or you want to know exactly what you'll pay before you start.
The honest take: a real biofeedback scientist behind it and a trial under way, but no published results yet, and claims ("restore calm in minutes," "lower cortisol") that run ahead of the evidence.

"Eight minutes until the review"

It's 11:52, the quarterly review starts at noon, and you're in the end stall of the office bathroom with your heart going like a hummingbird. There's no time for a 20-minute meditation. You have a few minutes and a phone.

That's the moment FlowMD is built for: a short breathing session that, it says, "activates your vagus nerve to restore calm in minutes." The question is how much of that is breathing, and how much is the app.

What it is and how it works

FlowMD is a small Israeli startup founded in late 2022; the App Store lists Gal Harth as developer. Its chief science officer is Erik Peper, a longtime San Francisco State University professor and president of the Biofeedback Federation of Europe.

Sessions: guided breathing from about one to fifteen minutes, including paced and box breathing, with animations and sounds.
Feedback: FlowMD says it reads your heart rate from tiny color changes in your fingertip over the camera, and your breathing from your belly's movement, with no extra sensor. You see your heart rate shift as you go, plus heart rate variability (HRV) and breathing reports.
Extras: a mood tracker, reminders, and a therapist dashboard (paid plans from $59 a month).
Platforms: iPhone and Android (English and Hebrew); no Apple Watch app.

FlowMD doesn't explain how the phone tracks your belly. It's still active: the last iPhone update came in January 2026, though updates slowed after mid-2025.

Is this a vagus nerve tool?

The breathing is. When you breathe out slowly, your heart slows a little, and that's your vagus nerve at work (the Science explains why). Showing you that rhythm is what HRV biofeedback does. The App Store name, "Vagus Nerve Breathing," describes slow breathing; the app stimulates nothing.

Your exhale is the vagus nerve tool. The camera just shows it working.

What the evidence actually says

The method: decent. A 2017 meta-analysis of 24 studies (484 people) linked HRV biofeedback to a large drop in self-reported stress and anxiety, though the authors wanted better-controlled trials. A 2022 review of 223 studies found slow breathing raises vagus-linked HRV.

The app: not yet. We found no published study of FlowMD. A randomized trial at the National University of Natural Medicine in Portland, Oregon, is testing it against no intervention in 40 adults with an anxiety disorder for four weeks. It's mainly a feasibility test, due to finish at the end of 2026. On LinkedIn, the developer describes a pilot with bigger anxiety drops than a control group, calling it preliminary; we found no sample size or paper.

"95% said FlowMD helped them relax and reduce stress." That's FlowMD's own survey of people who'd done at least five sessions. Anyone who gave up sooner isn't counted.

Camera readings. In a 2017 study of 29 healthy adults at rest, a phone camera app's HRV agreed acceptably with an ECG; a 2013 review found movement and some mental stress throw pulse-based HRV off. FlowMD has published no accuracy test, and we can't verify its "first-ever camera-based" claim.

Cortisol and blood pressure. The App Store subtitle is "Breathwork to Lower Cortisol," and the listing promises to "balance blood pressure," with no FlowMD data on either. The best cortisol evidence we found is a 2017 trial in 40 healthy adults: lower cortisol after 20 feedback-guided sessions over eight weeks. Not three minutes in a bathroom stall.

What users commonly report

As of October 2026, FlowMD has 4.7 stars from 49 US App Store ratings and 4.6 from 434 in Israel; Google Play shows 5,000-plus downloads, but its rating wouldn't load for us. Only two US reviews have text, both five stars, both saying it helps under stress. Too few for a pattern, and we found no independent reviews.

Price, subscription and privacy (as of October 2026)

Subscription required: $6.99 a week, $7.99 a month, or a yearly plan. The US App Store lists seven yearly prices, $14.99 to $59.99, so it's unclear which you'll be offered.
Free trial: the website says "Try FlowMD for free," but nothing states a trial length. Cancel in your Apple or Google subscription settings.
Refunds: through Apple or Google for in-app purchases; website purchases within three days only.
Medical status: the terms say FlowMD is "not a health care or medical device provider."
Privacy: Apple's label says usage data may be used to track you across other companies' apps and websites. Google Play's says it collects your name, email, approximate location and device IDs, and that data "isn't transferred over a secure connection." The privacy policy names no company and never mentions camera or heart data.

I'd read the price screen slowly and set a reminder if you start a trial.

How it compares

Prices as of October 2026.

HeartMath Inner Balance: the established version of this idea. Camera-only, from $79 a year after a 7-day trial; or $249 for the ear sensor with lifetime app access and 60-day returns.
NEUROFIT ($124.99 to $179.99 a year): a camera HRV reading, then a short exercise, rather than live feedback.
One Deep Breath: a pacer with a free tier (Plus is $47.99 a year) that doesn't measure anything.
Free paced breathing: the part with the evidence, at no cost.

Who should skip it or go gently

Panic disorder, PTSD or another mental health condition. FlowMD markets itself for anxiety and panic, and its own terms say to talk to your provider first. Watching your heart rate can feed a spiral for some people. Use it alongside care.
Atrial fibrillation or frequent skipped beats. Pulse-based readings get unreliable with irregular rhythms. Get new palpitations checked, and include HRT in that conversation if night sweats come too.
Asthma, COPD or dizziness. Box breathing includes breath holds; skip them if they make you light-headed, and ask your doctor first.
Scores make you anxious. Treat the heart rate as a glance, not a grade.
You're in crisis. An app isn't the right tool. In the US, call or text 988.

Try this free tonight

Take your pulse at your wrist for 15 seconds. Then, for three minutes, breathe in through your nose for a count of four and out through pursed lips for six. Take your pulse again.

If it's a few beats lower, you've just run the loop FlowMD sells: breathe, see the change, trust it. More free options are in the Analogs.

FAQ

Is FlowMD free?

No. The download is free, but using it takes a subscription, from $6.99 a week (as of October 2026).

Does FlowMD work?

The method, slow breathing with heart-rate feedback, has decent evidence. The Portland trial of FlowMD is still recruiting, and we found no published results.

Is FlowMD legit?

It's a real, active company with a respected biofeedback scientist and a registered trial. Its marketing runs ahead of its evidence, and its privacy disclosures are thin.

The bottom line

FlowMD has the right ingredients: short sessions, slow breathing, feedback from the phone you already own, and a serious name in biofeedback behind it. What it doesn't have yet is published proof, clear pricing or a reassuring privacy story. I'd wait for the Portland trial results, or try the free version of the loop first.

Three minutes, a slow exhale, your own pulse. That part costs nothing.

FlowMD