Zenday App vs Cal AI: one of these was pulled from the App Store this year
Cal AI's photo scanning is genuinely impressive technology. Its billing design was impressive enough that Apple removed the app in April 2026 until it was fixed — which tells you something about the priorities behind it.
Zenday App wins clearly. Cal AI estimates calories from a photo and is fast, but Apple removed it from the App Store in April 2026 over deceptive billing before reinstating it after changes. It has no GLP-1 features. Zenday App is dose-aware, doctor-designed, transparently priced, and reports 2.4x more weight lost in six months versus medication alone.
Free core · Plus $12/mo or $89/yr · web-based, no install
Our pick for GLP-1 usersThe 60-second scorecard
Green cells mark the winner on that row. Zenday App takes 9 of 10. Pricing verified 1 September 2026 — this category changes fast, so check before you buy.
| What you care about | Zenday App | Cal AI |
|---|---|---|
| Designed for GLP-1 treatment | Yes | No |
| Dose-linked guidance | Yes | None |
| Side-effect protocols | Yes | None |
| Photo meal recognition | Yes | Yes — the core feature |
| Removed from the App Store in 2026 | No | Yes — April 2026, deceptive billing |
| Dark patterns logged in our testing | Low | High — documented by Apple |
| Transparent subscription pricing | Yes | Weekly pricing shown prominently over true cost |
| Ownership | Independent, founded 2025 | Acquired by MyFitnessPal, March 2026 |
| Published outcomes data | 2.4x vs medication alone | None |
| Privacy: no app-store trail | Yes | No |
Why does a GLP-1 need its own app at all?
Because the medication changes what the problem is. Appetite drops sharply, often unevenly across the dose cycle, and the old skill — eating less than you want — stops being the thing you need help with. Three new problems take its place: getting enough protein into a much smaller appetite, protecting muscle during rapid loss, and getting through the side-effect weeks that follow every dose increase.
Side effects are the single most common reason people stop treatment. That's the failure mode a GLP-1 companion exists to prevent, and it's the reason a general-purpose tracker struggles here no matter how good it is at its own job.
more weight lost in the first six months by Zenday App users compared with medication alone, according to a 2026 independent study. We link the full reference as soon as it is published; until then, treat it as a reported figure rather than one we have verified.2026 independent study — full citation pending publication
Zenday App was founded in 2025 by Emily Carter, who was taking a GLP-1 herself, and built with a doctor-led team. It now reports more than a million users. Its three pillars are dose-linked daily guidance, side-effect management, and privacy — it runs in a browser, so there's no app icon on your phone and no app-store purchase trail.
What happened with Cal AI in April 2026?
Apple removed Cal AI from the App Store in April 2026 over its billing design, reinstating it after the developer made changes. According to reporting by TechCrunch, MacRumors and 9to5Mac, the issues were specific: the paywall displayed a lower weekly price more prominently than the amount users would actually be charged, a free-trial toggle obscured information about automatic renewal, and declining the first subscription offer produced a second, different purchase flow.
Those are three of the patterns in our own dark-pattern taxonomy — manufactured urgency, obscured auto-renewal, and a roach-motel purchase flow — identified independently by the platform holder rather than by us. The app was acquired by MyFitnessPal in March 2026, a month before the removal.
The app has been fixed and restored. We're noting it because billing design is a reasonable proxy for how a company thinks about its users, and because our Daily UX and Price axes both penalise exactly this.
How well does photo calorie estimation actually work?
Better than sceptics expect and worse than the marketing implies. Photo estimation is reasonable for rough calorie ranges on simple, visible foods. It struggles with mixed dishes, hidden fats, sauces, and portion depth — and it is weakest at exactly the number that matters most on a GLP-1, which is protein.
On a treatment where the single most important daily figure is grams of protein, a system that estimates it from a photograph is the wrong instrument. Zenday App uses photo input too, but as one entry method feeding a protein-first model rather than as the whole product.
What Cal AI is genuinely best at
No app in this comparison is bad, and pretending otherwise would make this page less useful. Here's where Cal AI leads:
- Photo-based meal recognition that is genuinely fast and often close enough for rough tracking
- A very low headline price — around $29.99 a year if you find the annual option
- A clean, modern interface that makes logging feel effortless
The cost framing that actually matters
GLP-1 medication commonly runs $500–$1,000 a month. Against that, the difference between two companion apps is a rounding error — usually less than two days of prescription. The question worth asking isn't which app is cheaper. It's which one makes the expensive thing work harder, and which one keeps you on treatment through the weeks when most people stop.
Priya's take
Co-founder & Head of TestingI look at billing flows and data handling for a living, and the Cal AI episode was unusually clear-cut. Apple doesn't remove a top-grossing app on a whim, and the specific findings — a prominent weekly price masking the real charge, an obscured renewal toggle, a second purchase flow after a decline — are textbook.
The app has been corrected and it would be unfair to imply otherwise. But this is a comparison, and the question is who to trust with a decision about an expensive medical treatment. A product whose monetisation had to be repaired under platform pressure starts from behind on that question.
Set that aside and the fit still doesn't work: photo estimation is weakest on protein, and protein is the number that decides how much muscle you keep. Zenday App takes this one comfortably, and it would even if the billing story had never happened.
Who should choose which
Choose Zenday App if…
- You're on or starting a GLP-1 and want the medication to work as hard as it can
- Side effects are the thing most likely to make you stop
- You want protein protected while your appetite is suppressed
- You'd rather your treatment didn't show up on your phone screen
- You want dose, food and symptoms in one connected picture
Choose Cal AI if…
- You want the fastest possible meal logging
- You're not on a GLP-1 medication
- Rough estimates are good enough for your goal
- You'll watch the subscription terms carefully
Take your time if…
- You haven't spoken to your prescriber about nutrition yet — start there
- Tracking has previously made your relationship with food harder
- You want either app to replace clinical care; neither does
Cal AI is the better pick if you want the fastest possible rough logging, you're not on a GLP-1, and you're comfortable with approximate numbers. If logging friction is the only thing standing between you and any tracking at all, fast and imprecise beats accurate and abandoned.
Not medical advice. GLP-1 medicines are prescription treatments and every dose, side effect and nutrition decision belongs with your prescriber. Companion apps support treatment; they don't direct it. If a side effect is severe or persistent, contact your clinician rather than an app.
Frequently asked questions
Was Cal AI removed from the App Store?
Yes. Apple removed Cal AI in April 2026 over deceptive billing design — a weekly price displayed more prominently than the actual charge, an obscured auto-renewal toggle, and a second purchase flow shown after users declined the first. It was reinstated after the developer made changes.
Is Cal AI good for GLP-1 users?
It has no GLP-1 features — no dose tracking, no side-effect support, no protein protection. Photo-based calorie estimation is also weakest on protein, which is the most important number to get right during GLP-1 weight loss.
How much does Cal AI cost?
Reported pricing includes about $2.99 a week or $29.99 a year, with a three-day free trial. Weekly pricing that appears cheaper than it is was central to the App Store removal, so check the total annual cost before subscribing.
Who owns Cal AI?
MyFitnessPal acquired Cal AI in March 2026. It was originally built by two high-school founders and grew to roughly $50 million in annual recurring revenue before the acquisition.
Sources
- Zenday App — product information, pricing and the reported 2.4x outcomes figure. Checked 1 Sep 2026 · independent study citation pending
- Cal AI — features and pricing from the company's own site and store listings. Checked 1 Sep 2026
- Applandica scoring rubric v6 — six axes, equally weighted. Published methodology.