Doydum is an iPhone app for keeping track of what you eat, with a pixel companion called Doy. To do that, it has to hold some personal things: your meals, your weight, your water and your steps. This page explains in plain words what Doydum collects, why, who helps us process it, how long we keep it and what you can do about it.
The short version: your data is used to run the app for you. There are no ads and no tracking, and we never sell your data. You can export a copy or delete everything from the app at any time.
Who is responsible for your data
Doydum is made by Mehmet Sumer, an independent developer based in Turkey. He decides how your data is used in Doydum and is responsible for it (the “data controller”). For any question or request about your data, write to support@doydum.app.
This policy covers the Doydum app for iPhone and the doydum.app website. The website has its own short section near the end of this page.
What we collect and why
We only collect what a feature needs. Here is everything, grouped by what it is for.
| What | Why we need it | How long we keep it |
|---|---|---|
| Your plan: birth date, sex (for the calorie formula), height, weight, goal, goal weight, activity level, weekly pace, meal rhythm, units, language and time zone | To calculate your daily targets and show your plan | As long as you have an account |
| Meals and nutrition: meal names, times and amounts; calories, protein, carbs and fat; your own foods, favourites and recent foods; the AI’s confidence and your edits | Your food diary, daily totals, progress charts and the farm | As long as you have an account, or until you delete the meal |
| Meal photos you scan, compressed to at most 1,280 pixels | To estimate the meal you asked about. Once you save the meal, the photo stays with it so your meal gallery can show it | Until you delete the meal or your account. If a scan fails or is refused, or you don’t save the review, the photo is deleted (an unsaved review expires after 24 hours) |
| Scan hints: the optional note you add to a scan | To make that estimate better | With the scan record, as long as you have an account |
| Weigh-ins | Your weight chart, milestones and plan | As long as you have an account, or until you delete the weigh-in |
| Water: each glass you add or undo, including from the widget | Your water total, target and reminders | As long as you have an account |
| Steps: daily step totals from your iPhone’s motion sensor, and the recent readings they are calculated from | Your step chart, your step target and the stone path on the farm | As long as you have an account |
| Doy’s insights and chats: the notes you ask for, your questions, Doy’s replies and any photos you send in a chat | To answer you | 30 days (insights: from when you ask; chats: from the last message), then deleted automatically |
| Streak and farm progress: away stretches, a mended day, rewards and furniture earned | The forgiving streak and Doy’s farm | As long as you have an account |
| Daily AI usage counts | To apply daily limits, such as 30 scans a day | As long as you have an account |
| Account: an identifier from Sign in with Apple, stored only in scrambled (hashed) form; a random customer number for purchases; sign-in sessions for your devices; an encrypted Apple token used only to disconnect Sign in with Apple when you delete your account | To sign you in and keep your data yours | As long as you have an account; each sign-in session lasts up to 30 days |
| Purchases: which plan you have, its status and renewal dates, received through RevenueCat | To unlock Doydum Pro | As long as you have an account (see “How long we keep your data” for billing records) |
Doydum doesn’t ask Apple for your name or email address and doesn’t store them. We never receive your payment card details: Apple handles payment.
Health information is sensitive. We use it only for the features you use, never for advertising, and you can change or delete it at any time.
What stays on your iPhone
Some things never leave your phone:
- Reminders. Water reminders, meal reminders, the evening day summary and, if you choose, a reminder before a trial ends are scheduled by your iPhone itself. Doydum has no push server and doesn’t ask for a push token.
- Motion data. Steps are read from the iPhone’s motion sensor (Core Motion) only after you allow it on the Progress screen. Doydum reads the last seven days when you open the app, and only daily totals are sent to your account. There is no continuous background collection and no connection to Apple Health.
- Preferences such as theme and language, and your setup answers until you sign in.
- Your sign-in session, kept in the iPhone’s secure storage.
- The widget keeps only today’s water, your water goal and a scrambled account key. Never meals, weight or steps.
When AI is involved
Doydum’s photo scan uses Google’s Gemini models, with Anthropic’s Claude as a backup; the other AI features use Anthropic’s Claude models. Each feature sends only what it needs, and only when it runs:
- Photo scan: the meal photo and your optional hint, to estimate the meal. They go to Google’s Gemini, and to Anthropic’s Claude only if Gemini can’t answer.
- Correcting a meal in words: your note, the meal’s items and its photo if it has one, to the same models as the photo scan. The note itself isn’t kept; the corrected meal is, once you save it.
- Ask AI (unknown barcodes): the photo of the pack and the barcode. The pack photo is deleted as soon as the answer comes back. Nutrition facts read from a label or found on the web may be saved for that barcode so the next person gets them straight away, without anything about you.
- Doy’s insights: when you tap Ask Doy on a chart, your plan details (such as age, sex, height, starting and latest weight, goal, pace, activity level and targets), the period’s daily totals and, for the calorie chart, the last 14 days’ meal names, times and nutrition.
- Chat with Doy: the same plan details and chart data as the note you’re chatting about, the note itself, the conversation so far and any photos you add.
- Doy’s daily lines: up to twice a day, a short summary of your day in words (for example, how yesterday went compared with your plan, whether today’s water and steps are on track, your streak and which meals you plan; for weight, only whether the trend is heading toward your goal), so Doy can greet you in his own words.
- Doy’s food reactions: only the name of a food, with nothing about you, so Doy can react to it. Reactions are shared by everyone who logs that food.
Our servers don’t write the content of AI requests or answers to logs. What you see in the app (a scan result, Doy’s note, a chat) is stored with your account as described above. Google (for photo scans) and Anthropic process this data on our behalf to produce the answer. AI answers are estimates and can be wrong; see the Health and AI notice.
Who processes your data
A few companies help run Doydum. They process data only to provide their part of the service, under their own terms for business customers.
| Company | What they do | What they receive |
|---|---|---|
| Convex | Our backend: database, file storage and server functions | The account data described above, including meal and chat photos |
| AI for photo scans and meal corrections (Gemini) | The meal photo, your optional hint and any correction you write, as listed above | |
| Anthropic | AI for Ask AI, Doy’s insights, chats and daily lines, and for photo scans and corrections when Gemini can’t answer | Only what each feature sends, as listed above |
| RevenueCat | Manages subscriptions | A random customer number, which plan you have and purchase events. No health data |
| PostHog | Product analytics for the app and this website, with servers in the United States | Usage events and the screens or pages opened, with device and app details and an approximate location from your IP address; after sign-in, your account’s random identifier and whether you have Pro. No health data, meal contents or photos. See “Usage data” and “This website” |
| Apple | Sign in with Apple and App Store payments | Your sign-in and your purchase, under Apple’s own privacy policy. Doydum never sees your card |
When you scan a barcode, our server also looks up the barcode number in Open Food Facts, a public food database; nothing about you is sent. The product’s public photo may then load on your phone from Open Food Facts’ servers.
Doydum includes no advertising, attribution or crash-reporting SDKs. Its only analytics SDK is PostHog’s, and it follows the usage data switch.
Usage data
Doydum shares usage data by default so we can see where setup and meal logging get stuck and fix them. It is used only to improve Doydum: never sold, never shared with advertisers, never used for ads. You can turn it off any time in Settings (Legal and data → Usage data), and Doydum works the same either way.
While it is on, the app sends usage events (for example, that a setup step was completed, or that a meal was logged and how: by photo, barcode or by hand) to Convex, our backend, and to PostHog, our analytics service. PostHog also records which screens you open and when the app is installed, updated, opened or closed, along with your device model, operating system, language, app version and an approximate location (country and city) from your IP address. After you sign in, both link events to your account’s random identifier, and PostHog also notes whether you have Pro. Events never include health answers, meal contents, photos or amounts, and PostHog never records your screen.
Convex keeps events for 90 days. PostHog keeps them for as long as our PostHog plan sets, at most seven years, unless we delete them sooner. Turning usage data off stops both: nothing more is sent to Convex or PostHog from this device, and this device’s measurement history at Convex is deleted (you can export it from the same place first). Events PostHog has already received aren’t deleted automatically: write to support@doydum.app and we’ll delete them.
No ads, no tracking, no selling
- Doydum shows no ads.
- Doydum doesn’t track you across other companies’ apps or websites and doesn’t ask for your advertising identifier.
- We never sell your data or share it for advertising.
- We don’t use your health data to market anything to you.
How long we keep your data
- Your account data stays as long as you have an account, unless you delete a piece of it earlier (a meal, a weigh-in, a glass of water).
- Meal photos stay with their meal. Deleting a meal deletes its photo, unless a copy of that meal you added to another day still uses it.
- Doy’s insights are deleted 30 days after you ask; chats, with their photos, 30 days after the last message.
- Usage data is kept for 90 days at Convex. PostHog’s copy is kept as long as our PostHog plan sets, at most seven years, unless we delete it sooner.
- Sign-in sessions last up to 30 days.
- When you delete your account, everything above is erased, photos first. A deletion receipt with no personal data is kept for 30 days so the status screen can show progress. Subscription events we received are kept for accounting with every identifier linked to you removed, and your customer record at RevenueCat is deleted. Apple keeps its own purchase records. Usage events already at PostHog aren’t erased automatically; write to us and we’ll delete them.
- Backups kept by our providers are overwritten on their own schedule.
More about how account deletion works.
Your rights and choices
You’re in control of your data. Wherever you live, you can:
- Access and export it. Open Settings (the gear on the Today screen) → Legal and data → Export a copy of my data. You get a JSON file with your profile, meals, water, steps, weight, Doy’s notes and chats, your streak and farm progress and your subscription status. Photos aren’t inside the file; they stay in your meal gallery.
- Correct it. Edit or delete meals, water and weigh-ins where you see them, and change your goals in Settings. For anything you can’t change in the app, write to us.
- Delete it. Settings → Account actions → Delete my account and data. See how deletion works.
- Object or say no. AI features run only when you use them, usage data can be turned off in Settings, and reminders and step access are opt-in. You can turn any of them off again.
You can also write to support@doydum.app to ask what we hold, to have it corrected or deleted, or to object to a use. We answer within the time the law sets, at most 30 days. Depending on where you live, for example under Turkey’s personal data protection law (KVKK) or the EU’s GDPR, you can also complain to a data protection authority; in Turkey, that is the Personal Data Protection Authority (KVKK).
How we protect it
Data travels between the app and our backend over encrypted connections. Your sign-in session is kept in your iPhone’s secure storage, access to the backend is limited to the developer, and each account can only reach its own data. No system is perfectly secure, but we work to keep yours safe, and if something happens that affects your data, we’ll inform you as the law requires.
Data across borders
Our providers may store or process data on servers outside Turkey, for example in the United States or the European Union. When your data moves across borders, we rely on the safeguards that data protection law requires for such transfers. For example, PostHog, which runs the app’s and this website’s analytics, stores its data in the United States.
Adults only
Doydum is for adults aged 18 and over; setup asks for your birth date. It isn’t meant for children, and we don’t knowingly collect data from anyone under 18. If you think a child has used Doydum, write to us and we’ll help remove the data.
This website
- To see how many people visit and how quickly the pages load, doydum.app uses Cloudflare Web Analytics. When a page opens, a small script from Cloudflare reports the page’s address, the site that linked to it, your country, your device type, browser and operating system, and how long the page took to load. It sets no cookies and builds no profile of you; Cloudflare states that it does not collect or use visitors’ personal data. We see only totals, such as visits per page.
- To see how the site is used and make it better, doydum.app also uses PostHog, whose servers are in the United States. It records the pages you open and leave, the links and buttons you click (such as the App Store badge, the homepage tour and the scan demo, or that a calculator or the food search was used), the site that linked to the page, your browser, device type, screen size, language and an approximate location (country and city) from your IP address. It keeps a random identifier for your browser in a cookie and in local storage, so repeat visits count once. It doesn’t record your screen, and it never receives what you type or choose in the calculators or the search box. Choose Decline in the cookie notice and PostHog stops collecting on this browser and removes its cookie; you can change your mind any time with Cookie settings at the foot of every page.
- The calculators run entirely in your browser. What you enter stays on your device; PostHog only hears that a calculator was used.
- Besides PostHog’s identifier, the site uses your browser’s local storage only to remember small preferences, such as your cookie choice or whether you’ve dismissed the companion on the page.
- The site is delivered by Cloudflare. Like the servers of any website, Cloudflare’s process basic technical data, such as your IP address, to deliver the pages and keep the site secure.
Changes to this policy
If Doydum changes how it uses your data, we’ll update this page and the date on it. For important changes, we’ll also let you know in the app before they apply.
Contact
Questions, requests or complaints about privacy: support@doydum.app. Mehmet Sumer, independent developer, Turkey.