Terms of Service

Last updated: 29 August 2026

Before anything else

Three things matter more than the rest of this document, so they go first.

1. Geddy estimates. It does not measure. Every number it shows you — the vitamin D your skin produced, the minutes until you burn — is the output of a model applied to a weather forecast. The app cannot see you, cannot tell whether you are in shade, and cannot know what your skin is actually doing. Do not treat a burn ceiling as permission to stay out. Section 3 explains this properly, and it is the most important section here.
2. Geddy is not medical advice and is not a medical device. It does not diagnose, treat, or monitor anything. Do not use it to decide on supplementation, to manage a diagnosed deficiency, or in place of a blood test or a doctor.
3. Your subscription is billed by Apple, renews automatically, and is cancelled in your Apple Account settings — not by emailing us. We explain exactly how in section 8.

1. Who you are agreeing with

Geddy is made and operated by Tagir Aiupov, a sole proprietor based in British Columbia, Canada ("we", "us", "our").

Geddy is a one-person operation run from a home office, so we do not publish a street address. Email reaches us directly and is the fastest way to get an answer.

Email: [email protected]

These Terms of Service (the "Terms") are a binding agreement between you and us, covering the Geddy iPhone app, its Live Activity, and any related services that link to them (the "Services").

By downloading or using Geddy, you agree to these Terms. If you do not agree, do not use the Services. You may stop at any time by deleting the app.

Your use of Geddy is also governed by our Privacy Policy and our End User Licence Agreement, both of which form part of this agreement.

2. What Geddy is

Geddy is an app for iPhone that tells you when the sun at your location is high enough to produce vitamin D, estimates how much a session produced, and holds that session inside a burn ceiling.

It computes the sun's elevation for your coordinates and the date; treats roughly 45° of solar elevation as the threshold below which useful UVB production falls away, which defines the day's window — including the months when there is no window at all; fetches the current UV index and cloud cover from Apple WeatherKit; combines those with your Fitzpatrick skin type, exposed skin fraction, and age to produce an estimated IU figure with bounds; derives a burn ceiling from the minimal erythemal dose for your skin type at the current UV index; runs a Live Activity while a session is going; sends a time-sensitive notification when you reach the ceiling; logs each session; writes sessions to Apple Health as Time in Daylight; and lets you record blood 25(OH)D results so you can chart the model against your actual lab work.

There is no account and no sign-in. Your history is stored on your device and synced to your own iCloud account, so it reaches your other devices and survives a lost phone. It goes to Apple, on your behalf, and not to us: we hold no copy and cannot read yours. You can switch sync off in iOS Settings at any time and the app works exactly the same.

3. Safety, and the limits of the model

Read this section. It is the one that matters.

The dose estimate is provisional

The vitamin D figure Geddy shows you is a model output, not a measurement. Its structure follows the published literature, but the specific coefficients it uses have not been traced to a named source, and the app says so wherever the figure appears. It is there to give you a relative sense of a session, not an authoritative quantity.

Do not use it to make a health decision. Do not start, stop, or change a vitamin D supplement because of a number in this app. Do not treat reaching a daily IU goal as evidence that your levels are adequate. The only way to know your vitamin D status is a blood test ordered by a doctor. That is precisely why the app lets you log those results: measurement corrects the model, never the other way round.

The burn ceiling is an estimate, not a guarantee

The burn ceiling is computed from a published relationship between the UV Index and erythemal irradiance, applied to the minimal erythemal dose commonly quoted for your skin type. The model deliberately errs toward stopping sooner. It can still be wrong, and it can be wrong in the direction that gets you burnt.

It has no way of knowing:

• whether you are actually in the sun, in shade, under cloud that arrived after the last reading, or indoors
• whether you are wearing sunscreen, and whether you reapplied it
• how much skin you actually have exposed, beyond what you told it
• that you are at altitude, on snow, on water, or on sand, all of which reflect and intensify UV substantially
• that you are taking a photosensitising medication, or have a condition that changes how your skin reacts
• that the UV index it was given, which came from a weather service, was wrong or stale for your exact spot

You are responsible for your own skin. Use shade, clothing, and sunscreen. If your skin starts to redden, tingle, or feel hot, go inside — whatever the app says. Never treat "time remaining" as permission to stay out.

Geddy is not medical care

• Geddy is not medical advice, is not a medical device, and does not diagnose, treat, cure, prevent, or monitor any condition. Always seek a qualified professional for questions about your health, and never delay professional advice because of something in this app.
• Talk to a doctor before using Geddy if you have a history of skin cancer or precancerous lesions, a photosensitivity disorder such as lupus or porphyria, a condition affecting vitamin D metabolism such as kidney or liver disease, sarcoidosis, or hyperparathyroidism, or if you take any medication that increases sun sensitivity — including some antibiotics, diuretics, retinoids, NSAIDs, and chemotherapy agents.
• Ultraviolet radiation causes skin cancer and photoageing. No amount of sun exposure is risk-free, and there is no such thing as a safe tan. Sunburn, particularly in childhood, is strongly associated with melanoma. Geddy is a tool for bounding deliberate exposure, not an endorsement of it, and reasonable clinicians disagree about whether sun exposure is a sound way to obtain vitamin D at all.
• Do not use Geddy for a child, or to decide how long anyone else should be in the sun. The model is parameterised for the person whose profile is in the app.
• Vitamin D can be harmful in excess. Toxicity comes from supplements rather than sunlight, but a decision to supplement is a medical one and this app has no part in it.

Geddy is not designed to comply with sector-specific regulation such as HIPAA in the United States, and it must not be used as a system of record for anyone's health or clinical information.

Weather and location can fail

If WeatherKit is unreachable, Geddy will tell you the dose figures are unavailable rather than invent a UV index — but it may also show you readings that are current for a region rather than for the patch of ground you are standing on. Solar geometry is computed locally and is reliable; everything downstream of a UV reading inherits that reading's error.

4. Who may use Geddy

You must be at least 13 years old to use Geddy, or 16 if you live somewhere that sets 16 as the minimum age for consenting to data processing. If you are under the age of majority where you live, you may only use Geddy with the involvement of a parent or guardian who agrees to these Terms on your behalf.

By using the Services you confirm that you have the legal capacity to accept these Terms, that you will use Geddy lawfully, and that you are not located in a country subject to a Canadian or United States government embargo and not on any restricted-party list.

5. Your content is yours

You keep every right you already had in everything you record in Geddy — your profile, your sessions, your dose history, your saved locations, and your blood test results ("Your Content").

We do not receive Your Content, and we claim no licence over it. We do not host it, cannot read it, cannot moderate it, and will not use it — for training, for marketing, for improving the app, or for anything else. Geddy has no feed, no comments, no message boards, and no other users; nothing you record is ever published anywhere by us.

Health data specifically. Data read from or written to Apple Health is never received by us, never used for advertising or marketing, and never sold or shared. Section 4 of our Privacy Policy states this in full.

You are responsible for Your Content. Because it lives only on your device and in your own iCloud account — never on any system of ours — that responsibility is yours alone.

Feedback. If you send us a suggestion, bug report, or feature request, you allow us to use it to improve Geddy without owing you payment or credit. Please do not send us anything confidential this way — and please do not send us medical records.

6. Location and permissions

Geddy asks for three permissions, and works without any of them at reduced capability:

• Location (When In Use) so it can compute the sun's position where you are, and fetch the UV index there. Setting a position by hand is a fully supported alternative, not a fallback for a refusal.
• Health so it can write your sessions as Time in Daylight. It asks for write access only and reads nothing from Health.
• Notifications so the ceiling alert can reach you when your phone is face-down on a towel. This is the mechanism that interrupts you. If you refuse it, or silence it, nothing will tell you to cover up while the app is not on screen. That is a meaningful reduction in what the app can do for you.

Revoke any of them at any time in iOS Settings.

7. The Live Activity, and who can see it

While a session runs, Geddy shows a Live Activity on your Lock Screen and in the Dynamic Island. It is readable by anyone who can see your phone, without your passcode. That is the feature working as intended — the point is to check it without unlocking. Turn Live Activities off in iOS Settings if you would rather it did not appear.

The timing of notifications and the refresh of the Live Activity are controlled by iOS. We do not warrant that a ceiling alert will always arrive, or arrive on time. It is a scheduled local notification, and iOS decides when to deliver it. Do not rely on it as your only protection from a sunburn.

8. Subscriptions and payment

How you pay. All purchases are made through Apple's In-App Purchase system. Apple takes the payment, holds your payment details, and issues the receipt. We never see your card number or billing details. We are told only whether your subscription is active.

Free and paid use. Geddy is free to download, and the first three sessions are free, within your first two weeks. They are three in total, not three a day — the allowance does not refill, and it counts every session you start whether or not you finish it. The two weeks run from the first time you open the app, and they run whether or not you use a session in them. Both limits apply: whichever runs out first is the one that stops you.

The two weeks and the three sessions belong to you rather than to the handset. Both are recorded in your profile, which syncs through your own iCloud account, so deleting Geddy and installing it again does not start either one over, and neither does a second device.

After that, Geddy Pro is an auto-renewing subscription, and it is what runs a session: the timer, the burn ceiling calculated for your skin, and the alert that tells you to cover up. Read that carefully, because it is a limit on a safety feature. Once your three sessions are used, or your first two weeks are up, Geddy will not time your exposure or warn you before you burn until you subscribe. Nothing about the sun changes when the app stops counting, and you should not treat a locked app as a reason to stay out longer or as a reason to stay out at all.

What Geddy Pro adds. Sessions beyond the free allowance, and with them the session timer, the burn ceiling and its alert; the interactive arc of the day, which you can scrub to any hour; the hour-by-hour charts of UV index and the sun's angle; the panel of live readings on the home screen; and the day's almanac.

What stays free, for as long as you use the app and at no cost. Today's daylight window and the hours it runs; how many minutes of sun the app suggests for you today; the current UV index and the estimated time before you would burn, both stated on the home screen; your recorded skin type and settings; and everything you have ever logged — every past session, your blood results, your goals and your streaks — which you can always read, whether or not you subscribe.

Losing Pro never deletes anything. If a subscription lapses, everything you have recorded stays on your device and in your iCloud and remains readable.

Plans and prices. The plans available to you, the exact price, the currency, the billing period, and any introductory or free-trial offer are shown on the purchase screen and in the App Store before you confirm. Prices vary by country and may change; we will always show you the current price before you buy.

Free trials and introductory offers. Where an offer is available, its length and terms are shown before you confirm the purchase. Unless you cancel at least 24 hours before an introductory period ends, it converts automatically into a paid subscription and your Apple Account is charged. Apple's rules on introductory offers apply, and an offer can generally be used only once per Apple Account.

Automatic renewal. Subscriptions renew automatically at the end of each billing period. Your Apple Account is charged within 24 hours before the current period ends, at the then-current price, unless you cancel first.

How to cancel. Cancel in iOS Settings → your name → Subscriptions, or in the App Store app under your account. You must cancel at least 24 hours before the next renewal date. Deleting the app does not cancel your subscription. Cancelling stops future charges; your access continues until the end of the period you have already paid for.

Refunds. Apple handles all refunds under its own policies. Request one at reportaproblem.apple.com. We cannot issue refunds for App Store purchases ourselves, though we will help you where we can. Nothing here limits any statutory right of withdrawal or refund you have under consumer law where you live.

Price changes. If we change the price of a subscription you already hold, Apple will notify you and, where required, ask you to consent before the new price applies. You can always cancel instead.

9. What you may not do

Use Geddy as it was meant to be used. Specifically, do not:

• break the law with it, or use it to harm anyone
• use it to advise, instruct, or supervise anyone else's sun exposure, or present its output as a clinical or professional assessment
• copy, modify, translate, or create derivative works from the app, or reverse engineer, decompile, or disassemble it, except to the extent that applicable law expressly allows despite this restriction
• remove or obscure any copyright, trademark, or other proprietary notice, or the Apple Weather attribution that appears wherever weather data is shown
• resell, rent, sublicense, or redistribute the app, or make it available to others as a service
• interfere with the app's security features, bypass any free-tier limit, or tamper with entitlement checks
• use automated systems, scrapers, or bots against the Services, or extract WeatherKit data through the app for any purpose other than your own use of it
• use Geddy to build a competing product

Breaking these rules is a material breach of these Terms and ends your right to use the Services.

What is not on this list, deliberately: you are free to say whatever you like about Geddy. You may review it, criticise it publicly, and tell people what you think of it.

10. Our intellectual property

The Geddy app — its source code, design, interface, artwork, icons, written copy, name, and logo — belongs to us or our licensors, and is protected by copyright and trademark law. Your subscription buys access to the app, not ownership of it. Section 5 covers your side of the line: what you record stays yours.

Weather data is provided by Apple Weather and remains Apple's, subject to Apple's terms; the attribution and legal link shown in the app are a condition of that licence.

If you want to use our name or artwork for anything, ask us first at [email protected].

11. Availability, updates, and changes to the app

We work to keep Geddy running well, but we do not promise it will always be available, uninterrupted, or free of errors. We may update, change, suspend, or discontinue features as the app evolves, as iOS changes, or as third-party services change beneath us. Weather data in particular depends on Apple's WeatherKit service, which we do not control and which may become unavailable or change its terms.

If we ever discontinue Geddy entirely, we will give you reasonable notice through the app or the App Store so that you can save your history first. Because your history lives on your device and in your own iCloud account rather than on a service of ours, it does not disappear when a subscription lapses, when a service is withdrawn, or if we stop operating.

12. Your data, and the limits of what we can do

Your sessions, blood results, and settings are stored on your device and synced to your own iCloud account. We hold no copy of any of it, and we cannot restore it.

Sync means a lost or replaced phone usually costs you nothing: sign into the same Apple Account and your history comes back. But sync is a mirror, not a backup — a deletion travels to your other devices too, and there is no undo — and it only works while your iCloud account is available to you and Geddy is switched on in your iCloud settings.

So data loss caused by a lost, stolen, or broken device, by deleting the app together with its iCloud data, by a deletion you made and did not intend, by running out of iCloud storage, or by losing access to your Apple Account, is not something we are able to fix, and we are not liable for it. We have no copy to give you — that is the same design decision that means we never see your health information at all. Keep an encrypted device backup, and keep your own record of lab results. Issues with iCloud, iCloud Backup, account recovery, or your device are matters between you and Apple, under Apple's terms.

Our Privacy Policy explains this in more detail.

13. Disclaimers

To the fullest extent permitted by law, the Services are provided "as is" and "as available", and we disclaim all warranties, express or implied, including implied warranties of merchantability, fitness for a particular purpose, and non-infringement.

We specifically do not warrant that any dose estimate, burn ceiling, window time, UV index, or cloud figure is accurate, complete, or suitable for any purpose; that the Services will meet your requirements; that they will be uninterrupted or error-free; that a ceiling alert will be delivered, or delivered on time; that the Live Activity will refresh; or that any defect will be corrected. Reliance on any figure in this app is at your own risk, and section 3 explains why.

This does not take away rights you cannot lose. Some jurisdictions — including Canadian provinces, the European Union, the United Kingdom, and Australia — give consumers statutory guarantees that cannot be excluded by contract. Nothing in these Terms limits or excludes those rights, and if any part of this section conflicts with them, your statutory rights prevail.

14. Limitation of liability

To the fullest extent permitted by law, we will not be liable for indirect, incidental, consequential, special, exemplary, or punitive damages, or for lost profits, lost revenue, or lost or corrupted data, arising out of your use of the Services, even if we have been advised that such damages are possible.

Where we are liable, our total liability for all claims taken together is limited to the greater of (a) the amount you paid us for the Services in the twelve months before the claim arose, or (b) CAD $100.

These limits do not apply to, and nothing in these Terms excludes our liability for: death or personal injury caused by our negligence; fraud or fraudulent misrepresentation; gross negligence or wilful misconduct; or any liability that cannot lawfully be excluded or limited where you live.

15. Indemnity

If someone brings a claim against us because of how you used the Services — because you broke these Terms, broke the law, infringed someone's rights, or used Geddy to guide another person's sun exposure — you agree to cover the reasonable costs of defending it, including reasonable legal fees. We will tell you promptly about any such claim and give you the chance to be involved in its defence. This does not apply to claims arising from our own acts or omissions, and it does not apply to the extent your local consumer law says otherwise.

16. Ending this agreement

You may end it at any time by cancelling your subscription and deleting the app.

We may suspend or end your access if you materially breach these Terms — for example by tampering with the subscription gate or using Geddy unlawfully. Where it is reasonable to do so, we will warn you first and give you a chance to put it right. If we end your access without cause, we will refund the unused portion of any subscription you have already paid for, where Apple's systems allow.

Sections 3, 5, 10, 12, 13, 14, 15, 17, and 18 survive the end of this agreement.

17. Governing law and disputes

These Terms are governed by the laws of the Province of British Columbia and the federal laws of Canada that apply there, without regard to conflict-of-law rules. The United Nations Convention on Contracts for the International Sale of Goods does not apply.

Talk to us first. If something goes wrong, email [email protected] with the details. Most problems are a misunderstanding or a bug, and both are faster to fix by email than by lawyer. Please give us 30 days to resolve it before starting formal proceedings.

If that fails. Any dispute may be brought in the courts of British Columbia, Canada, and we both agree to their jurisdiction.

Your local rights come first. If you are a consumer, this section does not deprive you of the protection of the mandatory laws of the country where you live, and it does not take away your right to bring proceedings in your local courts where the law of your country gives you that right. Consumers in the European Union may also use the European Commission's online dispute resolution platform.

Small claims are always available. Either of us may bring an individual claim in a small claims court or equivalent tribunal, wherever it properly has jurisdiction.

California residents may reach the Complaint Assistance Unit of the California Division of Consumer Services at 1625 North Market Blvd., Suite N 112, Sacramento, CA 95834, or by phone at (800) 952-5210.

18. The rest

Apple. You acknowledge that these Terms are between you and us, not Apple, and that Apple is not responsible for Geddy or its content. Apple has no obligation to provide support for the app. Apple and its subsidiaries are third-party beneficiaries of these Terms and may enforce them against you. Maintenance, support, warranty, product liability, and intellectual property claims relating to Geddy are our responsibility, not Apple's, as set out in our End User Licence Agreement.

Changes to these Terms. We may update these Terms as the app and the law change. The "Last updated" date always shows the current version. If a change is material, we will give you reasonable notice in the app or by notification before it takes effect. If you keep using Geddy afterwards, you accept the new Terms; if you would rather not, you can stop using the Services and cancel your subscription.

Severability. If any provision is held unenforceable, it is severed and the rest stays in force.

No waiver. If we do not enforce a provision, that is not a waiver of our right to enforce it later.

Assignment. You may not transfer your rights under these Terms. We may transfer ours in connection with a sale or reorganisation of the business, and this agreement will continue to apply.

Entire agreement. These Terms, the Privacy Policy, and the End User Licence Agreement are the whole agreement between us about the Services.

Force majeure. Neither of us is liable for a failure to perform caused by something genuinely outside our reasonable control.

19. Contact us

Email: [email protected]

Tagir Aiupov, sole proprietor, British Columbia, Canada. If you need our full registered details in order to serve formal notice or to satisfy a regulator, ask by email and we will provide them.

If you have a complaint, write to us. We would rather hear it than have you leave.