Frequently asked questions

Annoying, and fixable. Almost always the purchase sits on a different Apple Account than the one signed in on the device.

1. Open the paywall in the app and tap “Restore purchases”.
2. Check under Settings → your name that you are signed in with the Apple Account you bought with. A subscription cannot be moved between accounts — not by you and not by us.
3. Close the app completely and open it again.

Still stuck afterwards? Then it is a bug on our side and we want to see it. Write to noah.sioly.ug@gmail.com.

In the App Store, not with us — we have no access to it. Deleting the app does not cancel anything; the subscription lives in your Apple account and keeps renewing.

1. Open Settings and tap your name at the top.
2. Tap Subscriptions.
3. Choose Cal 3D, then Cancel Subscription.

Or open the list directly: apps.apple.com/account/subscriptions.

Apple decides refunds, not us — Apple is your contractual partner for the purchase. The fastest route is reportaproblem.apple.com: sign in, pick the purchase, state the reason.

Independently of that you have a statutory right of withdrawal — and because the purchase contract is concluded with Apple, it is exercised there. What it covers, where to send it and when it expires early is on the cancellation and refunds page.

Not today, and not because we do not want to: there is no Android version yet. Even once there is, the App Store and Google Play are separate billing systems — a subscription bought in one cannot be carried into the other. You would cancel on the old side and subscribe on the new one.

Prices are set once the app is in the store — you will see them there before buying. We are not putting a number here while it is not binding.

Other apps estimate portion size from a single photo. But a photo has no scale — the same bowl of rice can weigh 120 or 280 grams and look identical in the image.

Cal 3D asks you to sweep around the plate for three seconds instead and measures the volume from the camera’s depth data. Volume times density gives a weight — the step others guess is measured here.

The whole calculation is laid out on the method page.

Then you correct it before saving — every ingredient and every amount is editable.

Worth knowing where the limit sits: measuring fixes the scale, not the recognition. If the model takes couscous for cauliflower rice, the portion is measured exactly and the calorie figure is still off. That is why the entry stays editable instead of being presented as final.

Honest answer: we do not have a solid figure of our own yet, and we are not inventing one.

What we have measured is the problem: the photo pipeline from which Cal 3D inherited its ingredient recognition sat at roughly 30 % calorie error across 28 weighed plates from the public Nutrition5k dataset — with a clear pattern, not random noise. That pattern is exactly what the measurement attacks.

As soon as a series of our own exists, it will appear with the date, the number of plates and a description of the setup on the method page.

Because it says so. Every entry carries a label: Measured or Estimated.

In case of doubt the app always decides for “estimated”. A number presented as measured has to have actually been measured — otherwise the label is worthless.

No. You can log any meal by hand or scan a barcode. The sweep is the route to a measured portion — it is an option, not an obligation.

Anything inside an opaque container is invisible to the camera. With soups and drinks the app measures the visible content; with cups, entering the amount by hand is more accurate.

With layered dishes — sauce over rice, cheese over a bake — it measures the outer shell. What lies underneath stays an estimate by the model.

The app needs iOS 17 or later. Volume measurement additionally requires a LiDAR sensor, which is fitted to the Pro and Pro Max models from the iPhone 12 Pro onwards — so not to older Pro models such as the iPhone 11 Pro.

On every other device Cal 3D works fully but labels its values as estimated. We say this before you buy, not after.

That is your call, and we do not want to make it for you: without LiDAR you still get barcode lookup, the food database and a diary for good, and the photo recognition with Cal 3D Premium — but not the measurement that makes Cal 3D special. That one needs the Pro and Pro Max models from the iPhone 12 Pro onwards.

Not yet — iOS comes first. Android is being built alongside it: the app already carries its Android icon set and its Android layout fixes.

The volume maths itself is written in Swift today, in a module of its own rather than inside the iOS screens, so that the port has something to port. A shared C++ core is prepared for it but still empty — we would rather say that than let you read a plan as a status.

We are not naming a date, because we cannot keep one yet. What holds Android up is not the app but the hardware: depth sensors vary far more across Android devices than across iPhones, and a measurement we cannot vouch for is worth less than an honest estimate.

For recognising the dish, yes — a vision model runs on a server for that. For the measurement, no: that happens entirely on your device.

Without a connection you can still log by hand and keep your diary.

Then they are gone, and we cannot get them back — there is no copy on our side, because your diary never leaves your device. That is the price of having no account, and we would rather name it than hide it.

The one thing that does preserve it is a device backup: an encrypted iCloud or computer backup includes the app’s data. If you restore the iPhone from such a backup, the diary comes back with it.

Planning to reinstall? Make a backup first. Deleting the app also does not cancel a subscription — see above.

Three things, in this order — the first two are quick:

1. Close the app completely (swipe it away in the app switcher) and reopen it.
2. Check for an iOS update and for an update to Cal 3D in the App Store. Most crashes we have seen were fixed in a version already released.
3. Restart the iPhone. Only then consider reinstalling — and read the previous answer first, because reinstalling deletes your diary.

If none of that helps, write to noah.sioly.ug@gmail.com with your iPhone model and iOS version. That usually saves two emails.

Three things can leave your device, each only when you ask for it: a single compressed photo of your meal, a food name you type into the search, or a workout you describe in your own words. Each goes through our own endpoint to OpenRouter and from there to Google Gemini so it can be recognised. We do not store any of them and write nothing to a log.

What we are not claiming: that the providers do not use them for training. We cannot assure that, so we do not write it down — and for typed text the intermediary makes no retention promise at all, while for images it does. Details, including who receives what, are in the privacy policy.

What never leaves the device: the measurement itself, your diary, and your body weight — the calories for a workout are worked out on your iPhone.

No — there is none. You never sign in, we keep no list of users, and your diary lives on your device.

No. That has a downside we state openly: if you delete the app or lose the device, the data is gone. A device backup via iCloud includes it — currently that is the only way to preserve it.

In the app via Profile → Account Actions → Delete Account — the menu is named that although there is no account — or by deleting the app. Both are described step by step on the delete your data page.

Only for counting: there is a cap of 120 analyses per day so that nobody can drain the service. The address itself is not stored but passed through a one-way function — it cannot be recovered from the result.

It is not published yet. We will name a date when we can keep it — which is also why this site shows no ratings and no user numbers.

Gladly. The most useful thing is weighing a plate, scanning it and sending us both numbers — that is how the measurement series still missing from the method page gets built. Write to noah.sioly.ug@gmail.com.