Privacy

Mernik app, beta, website and waitlist · Version 2 · 3 November 2026, edited the same day: the name Marko became Mernik, nothing else

This policy explains what the Mernik app, its beta, this website and the Mernik waitlist do with your personal data. It replaces version 1, which covered only the waitlist and this website.

In short

• Mernik plans your training from what you tell it, and from Apple Health and your calendar if you switch them on. We treat everything in your plan as health data, and we only store it or send it to the coach after you've agreed.
• Your plan is stored in the EU, in Ireland.
• Mernik's coach is Claude, an AI from Anthropic, a company in the US. It receives your plan, what you type and, if you connect them, your Apple Health and Apple Watch readings, but not your name, your email or your routes. Anthropic doesn't train its models on it, and deletes it within 30 days unless a message breaks its usage policy.
• No ads, no analytics, no tracking. We never sell your data, and Apple Health data is never used for anything but your plan.
• You can export your data or delete your account in the app at any time. Deleting it removes it from our database at once.

Who we are

Mernik is made by NIE DIGITAL LTD OOD ("NIE DIGITAL", "we"), a company registered in Bulgaria under UIC 204932502, with its registered address at Ovcha Kupel, bl.511, vh.V, Sofia, Bulgaria. We are the controller of the personal data described on this page. You can reach us about anything here at hello@mernik.app. We haven't appointed a data protection officer; Damyan Gaitanov answers privacy questions for NIE DIGITAL.

What Mernik is for, and who it's for

Mernik is a training coach: general guidance for healthy people, not medical advice and not a medical device. It doesn't diagnose, monitor or treat anything. Mernik is for people 16 or over, in every country: the app asks for your year of birth and stops if you won't turn 16 this year. If we learn that someone under 16 has an account, we delete it.

If you're 16 or 17, Mernik tells you that its training plans haven't been tested with people under 18, so take extra care: build up slowly, stop if anything hurts, and ask a parent, coach or doctor if you're unsure. Mernik doesn't set a weight-loss goal for anyone under 18, and the coach won't suggest one. Mernik also never plans a calorie deficit for you, sets a lower limit on protein, and the coach won't talk about restricting food or about supplements. Otherwise your training works as it does for everyone, from your own level.

What the app collects, and why

Your account

You can use Mernik without signing in: the app creates an anonymous account the first time it saves your plan or you buy Mernik Pro. If you save your plan with Sign in with Apple or Google, we also receive your user ID with them and your email address (with Apple, often a private relay address), and from Google your name and profile picture address. We keep your year of birth, time zone, units, when you agreed to store your data and which version of the consent text you agreed to, and whether you have Mernik Pro. Our hosting provider records the IP address and device type of each sign-in to keep accounts secure.

We use this to keep your plan safe and on your other devices, to make sure you're 16 or over, and to know whether you're under 18 (for the note above and the weight-loss rule). The legal basis is our contract with you to provide Mernik (Article 6(1)(b) GDPR).

About you

When you set up your plan on iPhone, Mernik asks for your gender (woman, man or non-binary), your year of birth, your height and your weight. If you choose "Allow Apple Health", it reads your date of birth, height, weight and sex there, and you confirm them. Mernik keeps only the year of your birth, and uses the sex in Apple Health only to suggest your gender: it never stores or sends it.

Mernik uses these to set your calorie and protein targets, to check that a weight goal and its pace are safe for your height and weight, to work out your heart rate zones, and to show exercises on a figure like you (if you're non-binary, you pick the figure). We also use your gender to compare your results with norms for men or women when estimating your level and starting figures, and to time suggestions about your weight trend; if you're non-binary, your results are compared with the men's norms. Your gender isn't shown to anyone, isn't shared, and never removes a plan or goal Mernik offers you. Your height and weight are health data, kept with your consent like the rest of your plan (below). You can change any of them in the app at any time. Until you agree on the consent card, they stay on your phone.

Mernik also asks about your training: how long you've trained and what you did before, when you were last at your best, any injury or pain you have now, how you sleep and how stressed you are, your equipment and where you train, and what you prefer (sports you like or don't, how long a session can be, the time of day, two sessions in a day). From these and Apple Health it estimates your level and offers three ways to train, each with its nutrition targets, and you pick one. Injuries, pain, sleep and stress are health data, kept with your consent like the rest of your plan. If Apple Health already shows how you sleep, that answer comes from it.

Your plan and your training

To build and adapt your plan, Mernik keeps:

• your goals, such as a race, a weight or a lift, with their dates (a weight-loss goal only if you're 18 or over);
• your markers, such as FTP, threshold and resting heart rate, a 5 km time, body weight, height and lift results;
• when you can train: minutes per day, training windows, and when you're away, with a reason if you give one;
• your plan, with each session's status (done, missed) and why it changed;
• what you log: effort, duration, distance, power, heart rate, sets and loads, weigh-ins, notes, the Sunday check-in (effort, weight, stress, sleep, motivation, soreness, any pain and where, days you can't train, exercises you like or don't, how the week's training felt, a note), and symptoms if you report them;
• a log of changes to your plan, and the plan before your latest change so you can undo it.

Much of this is data about your health. Mernik stores and uses it only with your explicit consent (Article 9(2)(a) GDPR), as part of our contract with you (Article 6(1)(b) GDPR). Every night, unless your plan is paused, Mernik moves your plan forward and may swap a hard session for an easier one when your recovery looks low. That is automated, but it only changes a training session, never anything with a legal or similar effect on you, and you can move or change any session.

Apple Health (if you switch it on)

With your permission in iOS, Mernik reads your workouts (type, date, time, duration, distance and average heart rate), body weight, heart rate variability, resting heart rate and sleep, starting 35 days before you agreed to store your data, and, once when you set up your plan, your date of birth, height, weight and sex (see "About you"), your workouts, resting heart rate, heart rate variability and weigh-ins of the last 90 days, your VO2max and your daily steps. It summarises those workouts on your phone into how much and how often you train each sport. That summary isn't stored: what stays with your plan is what Mernik works out from it, which is your weight, your height, your level, your longest recent run and, if you run, an estimated 5 km time. Your daily steps never leave your phone: Mernik uses them only to estimate how active you are for your calorie target. It writes only the workouts you record with Mernik. It uses what it reads to tick off sessions you've done, follow your weight trend and ease off when you haven't recovered. Heart rate variability, resting heart rate and sleep are kept for 60 days. Apple Health data is never used for advertising or marketing, never sold, and never shared except as this policy describes. You can switch it off in the Health app at any time. Taking back your consent in Settings → Your data also stops it.

On Apple Watch, with your permission there, Mernik records a guided session as a workout in Apple Health, with your heart rate, active energy and distance, and shows your heart rate during the session. Mernik keeps what you log for the session (that it's done, your effort, the minutes and sets), a reference to the workout so it isn't counted twice, and a summary of it: its sport, when it started and ended, whether it was indoors, its duration, average and maximum heart rate, time in each heart rate zone, calories, distance, pace or speed, climb, split times and sets. The heart rate readings themselves stay in Apple Health. Mernik uses the summary to follow what you actually did, adjust your plan and spot personal records, and keeps it with the rest of your training until you delete it.

For outdoor runs, rides and walks, if you allow location on the watch, the workout's route is saved in Apple Health and on your iPhone, where Mernik draws it on a route card. The route isn't stored on our servers and the coach never sees it. To draw it on a map in the app, your phone loads map tiles for that area from Apple.

Sharing a workout

After a session, a personal record or a season, Mernik can make a share card: an image of the session, made on your iPhone. You decide whether to share it, and where: through the share sheet, to any app you choose, or saved to Photos. Nothing is sent to us or anyone else until you do. A route card leaves out the ends of your route: the first and last 500 m aren't drawn, a route shorter than 2 km shows no line, and there's no map, street or place name. Heart rate appears only if you turn it on. The image file carries no location, time or device information. The text that goes with it links to our website or our App Store page, never to you or your session. To save to Photos, Mernik asks only to add images, never to see your library. Once you've shared a card, the app you shared it with handles it under its own terms.

Calendar links

Each session in your calendar carries a link that opens it in the Mernik app. The link holds a code that says nothing about you or the session: without the app, the page it opens shows nothing about your session.

Your calendar (if you switch it on)

With your permission in iOS, Mernik reads your calendar on your iPhone, 14 days ahead, to place sessions in your free time. Only the start and end of busy times leave your phone. Event titles, places and people never do. Past busy times are dropped.

The coach

When you talk to the coach, and when it helps you set up your plan or runs the Sunday check-in, Mernik sends Anthropic:

• what you type, word for word;
• a summary of your plan: your goals, your sports and equipment, your height and weight, your markers, when you can train, this week's and next week's sessions, how your latest session went against the plan (its time, distance, pace and split times, and, if it comes from Apple Health or your Apple Watch, its heart rate, heart rate zones, calories and power), any new personal records, your latest weigh-in and weight trend, your nutrition targets, and any symptom you've reported;
• whatever else in your plan the coach looks up to answer you: other sessions, with their exercises, loads, efforts, notes and the same measures, your personal records, your season's totals and your check-ins;
• what you told Mernik when you set up your plan (your training history, injuries or pain, sleep and stress, and preferences), the level Mernik estimated, the summary of your last 90 days of training and your VO2max. When you set up your plan, the coach uses these to explain the three ways to train it offers you;
• the earlier messages of the same conversation, with the plan summaries sent alongside them. A conversation ends after 12 hours without a message, or after 60 messages.

It doesn't send your name, email, user ID, year of birth, IP address, calendar events or workout routes. It does send whether a calendar is connected, each session's time, and, when your calendar leaves no room, that a day is full and how many free minutes you have. If you're under 18, it tells the coach only that, never your age. For recovery, it sends whether your heart rate variability is down, your resting heart rate is up or your sleep is short, with your 7-day heart rate variability and resting heart rate against your usual, and your sleep over the last three nights. If you agreed before 22 October 2026 and haven't agreed again, it sends whether they look low but none of the numbers above, and no heart rate, zones, calories, distance or splits. The coach can still see what Apple Health changed in your plan, such as a session ticked off or eased, but none of the readings. What you type is sent as written, so please don't put anything in it you don't want the coach to read.

Anthropic doesn't use this data to train its models, and deletes it within 30 days, unless a message is flagged for breaking its usage policy, which it may then keep for up to 2 years. We keep each conversation on our server for 30 days after its last message, and the app keeps its own copy on your phone. We also record how much each conversation costs, to keep the coach within a monthly limit per user (our legitimate interest in keeping Mernik affordable, Article 6(1)(f) GDPR); this holds no health data. If you report one of the coach's replies, we keep which reply and when, with the conversation, so we can look into it.

The coach is optional. Mernik asks for your consent before the first conversation, naming Anthropic, and your plan works on your phone without it.

Notifications

Session reminders are scheduled on your phone; nothing leaves it. If you allow notifications, the app stores a push token for your device so we can tell you on Monday that your new week is ready. That message goes through Apple's push service and contains no health data.

Your calendar subscription (if you add it)

Mernik can give you a private link to add your sessions to Apple Calendar or Google Calendar. Anyone with the link can see your sessions and whether you did them, and your calendar provider fetches it from its own servers. Keep the link to yourself. You can reset it in Mernik's settings, which stops the old link working.

Mernik Pro

You subscribe through Apple, which takes the payment: we never see your card or bank details. Apple tells us the subscription's product, its transaction IDs, its status, when it renews or expires and whether it will renew, and we keep that with your account to give you Pro. The legal basis is our contract with you (Article 6(1)(b) GDPR).

Security logs

Our hosting provider logs requests to our servers (IP address, device type, time, what was asked for and the result) to run and protect the service, for a few days. Our servers never log the contents of your plan. This is our legitimate interest in a secure service (Article 6(1)(f) GDPR).

What we don't do

No advertising, no analytics, no crash-reporting tools, no tracking across other companies' apps or websites, and no data broker. We don't sell your data or share it for marketing. We don't put your health data in iCloud.

The beta

Before Mernik's release, we test it with a small group of people through Apple's TestFlight.

• TestFlight: Apple runs TestFlight under its own privacy policy. When you join with a public link, Apple shows us how many people installed each build, how often the app was opened, crash reports, and the feedback you choose to send, with its screenshot, your device and its iOS version. We don't see your name or email unless you add it to your feedback. We use this to fix Mernik (our legitimate interest in a working app, Article 6(1)(f) GDPR).
• The weekly question: if we invite you to the beta from the waitlist, or you join the waitlist through a beta tester's invitation link, we email you one question a week during the beta, then a closing email and one at the launch. The beta list is part of the waitlist: a mark on your waitlist entry in our own database in Ireland, and the emails go through Resend. It rests on the consent you gave when you joined the waitlist, with its double opt-in, to emails about the beta and the launch (Article 6(1)(a) GDPR), and you can unsubscribe at any time with the link in every email.
• Your replies and feedback emails reach us at beta@mernik.app. We read every one. We write down what needs fixing without your name or address, and delete the emails 3 months after the beta ends.
• Quotes: we quote you on the App Store page or our website only if you send us a quote and say yes, with the name you chose (or none). You can withdraw that at any time and we'll remove the quote.

The waitlist and this website

The waitlist

If you join the waitlist, we keep your email address, when you agreed to our emails and which version of this page you agreed to, when you confirmed your address, and how you found us: the campaign name in the link you followed or, if there isn't one, the domain of the website that sent you here, such as instagram.com. We never record the full address of that page, and we don't ask for your name. We also keep the language of the page you signed up on (English or Bulgarian), so we write to you in it.

• To send you news about Mernik's launch and beta: the email that confirms your address, a few emails before and at the launch, and, if there's a place for you, an invitation to the beta. We do this because you agreed to it (Article 6(1)(a) GDPR). You can withdraw your consent at any time with the unsubscribe link in every email after the one that confirms your address, or by writing to us; it doesn't affect the emails we sent before.
• To see which channels bring people to Mernik, we count signups by where they came from. This is our legitimate interest in knowing where to spend our time (Article 6(1)(f) GDPR).

Until you confirm your address, we send you nothing else, and if you don't confirm it within 30 days of our last confirmation email, we delete it. We keep the waitlist ourselves, in our own database in Ireland. We don't use your email address for anything else: not for advertising, not to build a profile of you, and not in the Mernik app. Our emails have no tracking pixels and their links aren't rewritten, so we don't know whether you open them or what you click.

This website

This website uses no analytics, advertising or tracking pixels, loads nothing from other websites and sets no cookies of its own. It's hosted by Cloudflare, which processes technical data about each visit, such as your IP address, your browser type and the page you requested, to deliver pages and protect the site from abuse, and may set a strictly necessary security cookie to tell people apart from automated traffic. We rely on our legitimate interest in running a secure website (Article 6(1)(f) GDPR). The country Cloudflare reads from your connection picks whether prices show in euros or dollars; we don't store it.

Your consent, and taking it back

Before Mernik builds your plan (or, if you set it up earlier, the first time you open the coach), it asks for your consent to store your training and health data, including what you told it about you and your training and the summaries of workouts you record on Apple Watch, and to let the coach read it, Apple Health readings included. Nothing is ticked for you, and until you agree, your plan, and anything Mernik read from Apple Health while you set it up, stays on your phone and none of it is sent to us or to Anthropic. If you're 16 or 17, you give this consent yourself: from 16, the GDPR doesn't ask for a parent's consent anywhere in the EU.

You can take your consent back at any time in Settings → Your data. Mernik then stops sending your data and the coach stops, we delete your data from our server, and your plan stays on your phone. Taking consent back doesn't affect what we did before.

Who handles your data

We don't sell your data or share it for marketing. These providers handle it on our behalf, as our processors under data processing terms:

• Supabase Pte. Ltd. (Singapore) hosts Mernik's database, sign-in and servers in Ireland (on Amazon Web Services, eu-west-1).
• Anthropic Ireland, Limited, with Anthropic, PBC in the US, runs Claude, the AI behind the coach.
• Plus Five Five, Inc. (Resend) (US) sends our emails to the waitlist and the beta list. It sends them from Ireland and keeps no list, but it keeps a record of each email it sends, with the address, in the US.
• Cloudflare, Inc. hosts this website, receives the waitlist form, and forwards email sent to our addresses.
• Google Ireland Limited (Google Workspace) keeps our email, including support requests and beta replies.

These companies act on their own account, under their own privacy policies, for the parts you use with them: Apple (Sign in with Apple, Apple Health on your iPhone and Apple Watch, push notifications, TestFlight, the App Store and your subscription payment), Google (Sign in with Google), and your calendar provider (if you subscribe to your Mernik calendar).

Outside the European Economic Area

Anthropic and Resend are in the US, and Supabase, Cloudflare and Google use companies outside the European Economic Area, mainly in the US, for parts of their service. These transfers are covered by the EU–US Data Privacy Framework or the European Commission's Standard Contractual Clauses. You can ask us for details of these safeguards.

How long we keep it

• Your account, what you told Mernik about you, your plan, your logs, weigh-ins, check-ins and the summaries of your Apple Watch workouts: until you change or delete them or your account, or take back your consent. Your progress is measured over your whole history.
• An account you never saved with Apple or Google: deleted 30 days after it last synced, since no one can reach it after the app is removed.
• Heart rate variability, resting heart rate and sleep: 60 days.
• Calendar busy times: until the day has passed.
• Coach conversations: 30 days after the last message on our server; up to 30 days at Anthropic (see "The coach").
• The log of changes to your plan: 90 days.
• The coach's cost per user: 13 months, then only monthly totals without your account.
• Push tokens: until Apple reports them invalid, or you delete your account.
• Your subscription's record: until you delete your account.
• Security logs: a few days, as our hosting provider keeps them.
• Backups: when you delete your account, your data also leaves our database backups within 7 days.
• Support emails: 12 months after the last message.
• Beta feedback emails: 3 months after the beta ends; quotes you gave us, until you take back your OK.
• The waitlist: until you unsubscribe or ask us to delete it, and at the latest 30 days after the email announcing Mernik's launch (and in any case by 26 January 2028); unsubscribing deletes your address at once, and we keep only a record without it (where you came from, and when you joined, confirmed and left) until the whole list is deleted; an address that isn't confirmed, 30 days after our last confirmation email. Resend's record of our emails: for as long as we use Resend, and no more than 90 days after.

How we protect it

Your data travels encrypted. On our servers, every account can reach only its own data, and only our servers can change a plan. On your iPhone, your sign-in is kept in the iOS Keychain. Your calendar's event titles never leave your phone, and the coach gets a summary without your name or account.

Your rights

Under the GDPR you can ask us to:

• give you a copy of the personal data we hold about you;
• correct it if it's wrong;
• delete it, or limit how we use it;
• stop using it where we rely on our legitimate interest; and
• send it to you, or to another company, in a portable format.

Most of this you can do in the app, in Settings → Your data: export everything (JSON and CSV), or delete your account, which removes your data from our server at once. You can correct your plan and profile in the app. Deleting your account doesn't cancel a subscription: cancel it in your iPhone's subscription settings.

For anything else, write to hello@mernik.app and we'll reply within one month. If you're unhappy with how we've handled your data, you can complain to the Bulgarian Commission for Personal Data Protection or to the data protection authority where you live.

Changes

If we change this policy, we'll update its version and date at the top, and tell you in the app before a change that matters takes effect. If a change affects what we do with your health data or your email address, we'll ask for your consent again first.

Help with the app, exporting your data and deleting your account: mernik.app/support. NIE DIGITAL's own website has a separate privacy policy at niedigital.dev/privacy.