Privacy Policy
Effective 23 August 2026. Last updated 17 September 2026.
1. Who we are
HeightUp is an iPhone app operated by Deivid Velkov, an independent developer based in Bulgaria ("HeightUp", "we", "us"). For data protection purposes we are the controller of the personal information described in this policy.
You can reach us at support@heightup.app about anything in this policy, including a request to access or delete your data.
2. What this policy covers
This policy covers the HeightUp iPhone app and the website at heightup.app. It does not cover the App Store itself, or any other service you reach by leaving our app.
3. Information that stays on your device
HeightUp is built local-first. Everything below is written to your iPhone's app storage, and we hold no copy of it. Only the AI coach ever sends any of it off your phone, and only the numbers named in section 5:
- Your quiz answers: which mode you picked at setup, date of birth, sex at birth, race, current height and weight, shoe size, your biological parents' heights, the height you would like to reach, the goal you picked and what is motivating it, what has got in the way before, how confident you feel about your height, the sports you play, how often you are active, how you would describe your eating, how long you sleep, screen time before bed, usual wake time, how much you grew last year, whether you have relatives taller than your father, and whether you have underarm hair, more body odour or acne. Most of these never leave your phone at all. Your birth date and your parents' heights do not either: they are used on the device to calculate your age and your predicted height, and it is those two results, not the values behind them, that reach the coach.
- Your height history: every measurement you record at a check-in, with its date.
- Your daily logs: the sleep, nutrition and activity you record each day, including meals you save after a scan.
- Your progress: streaks, completed sessions, scores, and which parts of the app you have already been shown.
- Your settings: units, reminder preferences, and similar.
The single exception is the AI coach. If you use it, your age, sex, current height and weight, the goal you picked, and figures derived from your logs are sent with your message so the reply can reference your real numbers. Section 5 lists exactly what that summary contains. If you never open the coach, nothing in this section leaves your iPhone.
This information is under your control. Deleting the app removes all of it, and Settings → Delete Account & Data erases it without deleting the app, together with your account if you have one. Because it never reaches us, we cannot recover it for you if it is lost, and it is not included in any backup we hold, though it may be included in your own iCloud or iTunes device backup, which is governed by Apple's privacy policy rather than this one.
4. Your account, if you create one
An account is optional and is only required to use meal scanning and the AI coach. You create one with Sign in with Apple. When you do, we receive:
- A user identifier that identifies your account to our servers.
- An email address. If you chose "Hide My Email" when signing in, this is an Apple private relay address rather than your real one, and we never see your real address.
- Your name, where Apple gives it to us. Apple offers it only on the first sign-in and only if you agree to share it. Where it is given we store it with your account and show it on your profile screen; it is never sent to the AI features.
We do not ask for your phone number, your address, or any other contact detail. We never receive your Apple ID password.
5. The AI features
Meal scanning
When you photograph a meal, the photo is sent to our server, which forwards it to OpenAI to identify what is on the plate and estimate its nutrition. The result is returned to your phone, where you can edit it before saving.
We do not store the photo. It exists only for the length of the request, is not written to any database, file store or log of ours, and is discarded once the response is sent. We instruct OpenAI not to retain the request either. OpenAI may keep a copy for a limited period solely to monitor for abuse of its service, under OpenAI's own terms for its API; it does not use it to train its models.
The AI coach
When you send the coach a message, we send it to OpenAI together with the recent part of the conversation, so the coach can follow what you are talking about. That is your new message plus up to the last ten turns, including the coach's own earlier replies. Older turns are dropped and are never sent.
A summary of your progress goes with it, so the reply can reference your actual figures. It is assembled on your device and contains only numbers and fixed values: your age, sex, whether you are tracking yourself or your child, the goal you picked from the list, your units, your height and weight, your predicted height and its margin of error, your percentile, how much of your growth is already done, the odds of the height you said you wanted, how much you have grown since your last check-in and how fast, your daily targets, your sleep debt, your streak lengths, how complete your profile is, and the percentage of your targets you have hit. It contains no free text, no name and no contact details.
The request carries no account identifier. OpenAI receives your message and those numbers with nothing attached that identifies who you are.
Your message is first checked by OpenAI's moderation service. If it is flagged, the app replies with a fixed safety message and no coaching call is made.
We do not store your messages or the coach's replies. Our servers pass them through and keep no copy, and the app does not save them either: the conversation exists only while the coach is open and is gone the moment you close it.
6. Subscriptions and payments
HeightUp sells an auto-renewing subscription. All payment is handled by Apple through your App Store account. We never see your card, bank details or billing address.
We use RevenueCat to keep track of whether a subscription is active. Through RevenueCat we receive the product you bought, whether the subscription is active, when the current period ends, and whether it was refunded or cancelled. We store a copy of that status against your account so the app can unlock the paid features.
7. Usage counts, and why we keep them
The AI features cost us money on every call, so we count them. For each account we record, per day and per feature, how many calls were made, the number of tokens used and what those calls cost. This is what enforces the daily and monthly limits and stops a single account from running up an unbounded bill.
These counts are deleted automatically after 90 days by a scheduled job. They record that a call happened, never what was in it.
8. Server logs
Our server writes one line per AI request containing the account identifier, which feature was used, how the request ended (success, rate-limited, timed out, and so on), how long it took, and the token count and cost. This is how we find outages and runaway costs.
Nothing you typed, photographed, or that a model wrote back is ever written to a log. Our hosting provider also keeps standard infrastructure logs, which may include IP addresses, for security and reliability.
9. Device permissions
- Camera. Requested the first time you scan a meal, and used only while that screen is open. HeightUp does not access your photo library and does not record audio or video.
- Notifications. Optional. Every HeightUp notification is scheduled locally on your iPhone by the app itself. There is no push server, we hold no device token, and no notification data leaves your phone.
10. What we do not do
- We do not show advertising of any kind.
- We do not embed third-party analytics, attribution or advertising SDKs. HeightUp contains no such tracker.
- We do not track you across other companies' apps or websites, and we do not ask for the App Tracking Transparency permission.
- We do not sell your personal information, and we do not share it for cross-context behavioural advertising.
- We do not build advertising or marketing profiles about you.
- We do not use your photos or messages to train AI models of our own.
11. Who else processes your data
We keep the list as short as the product allows. Each of these acts on our instructions for the purpose shown.
| Provider | What they do for us | What reaches them |
|---|---|---|
| Apple | Sign in with Apple, App Store distribution, all payments | Your Apple sign-in, your purchase and subscription |
| Supabase | Our database, authentication and server functions | Your account identifier and email, subscription status, usage counts |
| OpenAI | Identifies the food in a meal photo, generates coach replies and screens messages for safety | The meal photo for the duration of the request, your coach message and the numeric progress summary |
| RevenueCat | Tracks subscription status across devices | Your account identifier and subscription events |
We may also disclose information if we are legally required to, or where it is necessary to establish or defend a legal claim, or to protect the safety of a user or the public. If HeightUp is ever sold or transferred, your information may transfer with it; we would tell you before that happened.
12. Where your data is processed
Our providers operate internationally, and our AI providers are based in the United States. If you are in the United Kingdom, the European Economic Area or Switzerland, this means your information may be transferred outside your country to somewhere with different data protection laws. Where that happens we rely on the European Commission's Standard Contractual Clauses, or an adequacy decision where one applies, as the safeguard for that transfer.
13. Our legal bases (UK and EEA users)
- Performance of a contract. Running your account, delivering the AI features you paid for, and managing your subscription.
- Legitimate interests. Counting AI usage to prevent abuse and control costs, and keeping security and reliability logs. We have balanced this against your rights and kept the data minimal and short-lived.
- Consent. Camera access and notifications, each of which you grant through iOS and can withdraw at any time in the Settings app.
- Legal obligation. Keeping records we are required to keep, such as for tax.
14. How long we keep things
| What | How long |
|---|---|
| Everything stored on your device | Until you erase it or delete the app. We hold no copy. |
| Your account (identifier, email, and name if Apple gave one) and subscription status | Until you delete your account. |
| Your parental confirmation, if you gave one | Held on your device with everything else, and erased with it. |
| Meal photos and coach messages | Not retained. Discarded as soon as the request completes. |
| AI usage counts | 90 days, then deleted automatically. |
| Server and infrastructure logs | A short rolling window set by our hosting provider. |
| Purchase records | As long as required for accounting and tax obligations. |
15. Your rights and how to use them
Two of them are buttons in the app:
- Export your data. Settings → export. You get a file containing everything the app holds about you, which you can save or send wherever you like.
- Delete your account. Settings → delete account. This erases your account and everything attached to it on our servers, then wipes the app's data from your device. It cannot be undone.
Deleting your account does not cancel your App Store subscription, because only Apple can do that. Cancel it in Settings → your name → Subscriptions on your iPhone, otherwise it will keep renewing.
Depending on where you live you also have the right to access, correct, delete, restrict or object to our processing of your personal information, to receive it in a portable format, and to withdraw consent at any time. Email support@heightup.app and we will respond within 30 days. We will never charge you or degrade your service for exercising a right.
If you are in the UK or EEA and you are not satisfied with our response, you can complain to your national data protection authority. In the UK that is the Information Commissioner's Office at ico.org.uk.
16. California residents
In the past 12 months we have collected the categories of personal information described in sections 4 to 8: identifiers, commercial information about your subscription, internet activity in the form of usage counts, and the content you submit to the AI features. We collect it for the purposes described in this policy and from you directly.
We have not sold personal information, and we have not shared it for cross-context behavioural advertising, in the past 12 months. We do not do either of these things. You have the right to know, delete and correct your personal information, and the right not to be discriminated against for exercising those rights. Use the in-app buttons above, or email us.
17. Children
What matters here is who is using the app, not only the age of the person being tracked. HeightUp has two modes, chosen at setup, and they are treated differently.
Tracking yourself: the AI features are for ages 13 and over. Below that the app switches them off. The AI coach and meal scanning are refused, and the option to create an account is not offered. Those are the only features that send anything anywhere, so with them off nothing that child records leaves the iPhone. Check-ins, daily logs, streaks and results keep working on the device exactly as described in section 3.
A parent or guardian tracking their child: the features work at any age, once you have confirmed. Before anything about a child under 13 is sent anywhere, the app asks you to confirm that you are the child's parent or guardian, that you are the one using these features, and that you agree to their information being sent as this policy describes. Nothing is sent until you do, and the app records the date you confirmed on your device, where it forms part of your data export and is erased when you erase your data. In that mode the account is yours, the coach addresses you rather than your child, and what reaches the AI features is information you chose to enter. We treat it as your data, with every right in section 15, including deletion.
The only thing that leaves the device in either case without touching the AI features is a subscription, if one is bought, which is handled by Apple and RevenueCat as described in section 6 and carries no health information.
We do not knowingly collect personal information directly from a child under 13. Information about a younger child reaches us only where a parent or guardian entered it and confirmed as described above. If we learn that a child under 13 has given us information themselves, we will delete it and close the account. If you believe that has happened, email support@heightup.app and we will remove it promptly.
If you are between 13 and 18, please use HeightUp with a parent or guardian's knowledge, and talk to them before making any purchase.
18. Security
Traffic between the app and our servers is encrypted in transit. Our database uses row-level security so an account can only ever read its own rows, our AI provider keys live only on the server and are never shipped inside the app, and account deletion is authenticated so that a request can only ever delete the account that made it.
No system is perfectly secure, and we cannot guarantee absolute security. If a breach affects your personal information we will notify you and the relevant regulator where the law requires it.
19. Changes to this policy
We will update this page when our practices change, and the date at the top will change with it. If a change is significant we will tell you in the app before it takes effect. Continuing to use HeightUp after a change means you accept the updated policy.
20. Contact us
Email: support@heightup.app