Scan your face with your phone to check your blood pressure: an Android app bought installs up to 148k in a month, then stopped

An Android app called Calyqo says a few seconds of scanning your face with the front camera can tell you your heart rate, blood pressure and blood glucose risk. Its installs went from 19k in mid-September to 146k by mid-October, then stopped abruptly around 18 October, and now it gets only a hundred or two new installs a day. This isn't a product that took off. It's a tool portfolio that moved a monetization template proven on iOS over to Android, bought volume for a month, did the math, and pulled out. Below: what it sells, where the traffic came from, where the money comes from, how crowded this category is now, and whether there's room for you.

A diabetic, Aug 12

On 2026 Aug 12, US user Roger Messner left a 1-star review on Google Play: "Not accurate at all, said I was pre-diabetic. I've been an adult diabetic since 2017. If they get this wrong, I can't trust anything else. Cancelled after the 3-day trial, uninstalling now." 20 people marked it helpful.

8 days later the developer replied: "Facial scan results are affected by lighting, camera angle, device quality, and other factors. They are for reference only and are not a medical diagnosis." The product name in the signature was still HealthyWell. It hadn't been renamed Calyqo yet.

On Sep 16, another US user, Steven Keesling, wrote almost the same thing: "It said my diabetes risk was low, but I already have diabetes. The blood sugar reading was well below my glucose meter. The pulse was roughly right."

These two reviews sum up the business. Users come in drawn by the curiosity of "no blood pressure cuff, no finger pricks." They start the 3-day trial. Some cancel once they see it's inaccurate, and some forget to cancel and become paying subscribers.

What it is

• You open the app, hold your face to the front camera for a few seconds, and get a "health report." The store listing says "advanced facial signal analysis and TOI™ technology … captures subtle facial blood-flow information," and the footer disclaims that it is not a medical device and should not be used for medical decisions.
• In-app purchases $9.99–$39.99,3 with a free trial, plus ads.
• It's listed under Tools, not Health. Health apps face stricter disclaimer and review requirements on Google Play, so listing as a tool likely sidesteps them (inference).
• Launched Jul 15 under the original name HealthyWell, package name still com.healthywell.com. Third-party aggregator AppBrain shows the old-name page saying it "disappeared from Google Play 29 days after launch," which may mean it was delisted once in August and later restored (unverified). The last update was Aug 20, with the release note just "Fix known bugs."
• The developer is called clf tools. The store page registers CTF Int Limited in Tsim Sha Tsui, Hong Kong. The support email domain is gyseouk.com, and some aggregators list the entity as GY WEB & SEO LTD in the UK. Its main products are two cleaner utilities: FluxClean (1.44M installs) and NeatPulse (630k installs), roughly 2.3M installs in total across the portfolio (Google Play, 11-06). It looks like a Chinese team running a tools portfolio through Hong Kong and UK entities (inference).

TOI™ is a registered trademark and patented technology of Canadian company NuraLogix. Its SDK got FDA 510(k) clearance in June 2026. Whether Calyqo licenses the term can't be verified externally. Most likely it just borrows the buzzword.

How 148k installs happened: a month of paid buying, then it stopped

Before late October, the curve is third-party (AppstoreSpy) estimates. From late October on, it's installs from Google Play. In the 11-06 days before, only 7 1,019 installs were added.

The curve has no organic-growth shape. It rises when ads run and drops when they stop. Searching "Calyqo" or "healthywell" on TikTok turns up 0 related videos. No one mentioned it on X in 90 days. No media outlet has covered it, and the only results online are APK aggregator sites. The name is invented, so nobody searches for it in the store. The rename also threw away whatever search volume the old HealthyWell name had. So the 140k+ installs were mostly bought. The likely channels are Google App Campaigns and/or Meta, though there is no direct evidence of the ad spend.

The users leaving bad reviews are US users comparing it against their own glucose meters, while the only country where it charted is the Philippines. Ad spend probably covered several English-speaking markets, including the US (inference).

Where the money comes from: trial-to-subscription, and the charts show only a slice

11-06 It charts in only one place: the Philippines Google Play Tools Top Grossing chart. Since late October its ranks went 41 → 44 → 48 → 46 → 50 → 53 → 50 → 51, steadily down. That chart had only 81 entries that day, so the bar to reach the top 50 is very low. Being on a top grossing chart doesn't mean much money. It doesn't appear in the top 200 of the US Tools Top Grossing chart.

The real money should be in US trial-to-subscription conversions, which the charts can't show, and the amounts are not public. The rank it still holds in the Philippines likely reflects users acquired before ads stopped who keep renewing, slipping a few places each week.

The ratings also show what the business looks like. The US store shows 3.1 stars. Of 628 ratings, 1 are 1-star and 259 are 5-star, with almost nothing in between. People who find it amazing give 267 stars. People who find it inaccurate give 5 star. 1

Who it competes with: one template, a whole row of apps

Calyqo is itself a copycat. The "face scan → scary risk score → 3-day trial → subscription" funnel first worked on iOS with Heartwell: Track Health (a Singapore company, launched March 2024). It has 5,927 US ratings with a 4.7 average, and peaked at #126 on the Health top grossing chart (App Store). Two third-party estimates of its revenue disagree badly: ScreensDesign puts monthly revenue at $350k, bumetric at about $3,500, a hundred-fold gap, and no one can say which is right.

This year a batch of near-identical template apps has appeared on Android:

The copy ("TOI™", "facial blood flow") and price ranges are nearly identical across these apps, which looks like one white-label SDK or one outsourced template (inference). Free alternatives also exist: Google Fit has long offered heart rate measurement via the camera, and Noom and several insurance and checkup apps in India have built face scanning in. The older finger-on-camera heart rate apps (Welltory, Instant Heart Rate) each have hundreds of thousands of ratings in the US.

What it gets wrong, every app in this category gets wrong too

Nearly all the bad reviews are about one thing: inaccuracy, especially for blood sugar and blood pressure. People with chronic conditions who have a blood pressure monitor or glucose meter at home compare it and leave, then write about it. Unvalidated blood pressure or blood glucose estimates are also exactly what Google Play's health policy scrutinizes most. The suspected delisting of the old name is the warning sign.

The opening lies in the opposite direction: promise only what a camera can measure reasonably well (heart rate, breathing, stress trends), stay away from blood sugar, and do trends and "see a doctor if" alerts well. But then you lose the "scan your face to learn your blood sugar" hook that makes people willing to try it, and conversion from paid acquisition drops. I haven't seen anyone pull off balancing those two.

If it were you

C You can learn a playbook here, but following this category isn't worth much.

• One-line verdict: This is the textbook case of "moving an iOS-proven subscription funnel to Android and buying a month of installs to see if it pays back." The product itself has no barrier to entry. The category already has a row of template apps, and even the people behind this one have stopped buying installs.
• Who it suits: Teams that already run an Android tools portfolio and have ad accounts and cash flow ready. clf tools is exactly that. It uses cleaner-app money to test a new vertical and drops it after a month or so if it doesn't work.
• Who it doesn't suit: Indie developers who have never run Google or Meta app ads, since there is no organic traffic here. People who want a long-term health product, because bad reviews and policy risk will follow you. Anyone unwilling to operate in the grey zone of "health claims."
• How to do it: If you must follow, don't copy the face-scan blood sugar angle. Copy the method. Each week, check which categories are charting on iOS Health and Tools Top Grossing thanks to a "trial + hard paywall," and look for ones that Android hasn't touched or does poorly. Validate ROI over a month or so with a small budget, and stop if it fails. If you do build face scanning, promise only heart rate and stress-type metrics you can measure reasonably well, and list it under Health and go through review honestly.
• How to acquire users: Paid acquisition only. Google App Campaigns and Meta, with creative built around the one-second curiosity of "scan your face on the phone to measure blood pressure." Test in one English-speaking country on a small budget first, and see whether trial-to-paid conversion covers acquisition cost.
• When to get in: There's no clear seasonal window, but template apps keep launching in waves. Calmia and Pulselio are already buying ads in more than a dozen stores, and the later you bid, the more expensive it gets.
• What would show you got it wrong: (1) Calyqo or Calmia restarts ad spend and holds a spot on the US Tools or Health top grossing chart for several months. That would mean renewals here are better than they look, and this isn't a one-off harvest. (2) Google Play mass-delists apps that scan faces to measure blood pressure or blood sugar. If that happens, the category is closed for good, and even the value of "learning the playbook" shrinks by half.