Privacy policy

Last updated 3 October 2026

Who is responsible

Tideline is made by Ben Jonas Goedeke, an independent developer. For anything about privacy, write to [email protected].

What stays on your phone

All of this is stored in the app's own storage on your iPhone and nowhere else:

• your daily entries: mood, symptoms, what you wrote, period days
• the answers you gave when you set the app up, and your cycle settings
• your reminder time, the colours you picked, and which tips you found useful

We have no copy. If you back up your iPhone to iCloud or a computer, the app's data is part of that backup, under your Apple ID and Apple's terms.

Speaking your entry

You can speak your daily entry instead of typing it. Tideline uses the microphone only while you hold the microphone button, and only after you allow it in the two iOS permission sheets. Your speech is turned into text on this iPhone itself: Tideline requires on-device recognition, so the audio is never sent to Apple or to us. If your iPhone cannot do it on the device, Tideline tells you and asks you to type instead rather than sending your voice anywhere. No recording is kept: the words become text in the box, and the audio is discarded.

Apple Health

Tideline reads from Apple Health only if you choose to import your period dates, and only after you allow it in the iOS permission sheet. It reads your recorded period days to find when each period started. It never writes to Apple Health. What it reads is kept on your phone like everything else, and is not used for advertising or given to anyone.

Sharing with a partner

Sharing is off until you switch it on. When you do, the app makes a link and you send it yourself, with whichever messaging app you like. The information is inside the link. It does not pass through any server of ours.

The link holds the name you typed, the first day of your last period, your usual cycle and period length, whether your cycle is regular, and, if you chose to share them, the notes you wrote about what helps you. It never holds your daily entries, your mood or your symptoms.

Your partner's copy of Tideline works out the rest from those dates. Because there is no server, a link cannot be taken back once it is sent. It stops working 45 days after you made it.

Reports and exports

The doctor's report (PDF) and the export of your record (CSV) are made on your phone. They go only where you send them from the iOS share sheet.

Reminders

Reminders are scheduled on your phone by iOS. No push service is involved.

Purchases

Tideline Plus is sold through the App Store. Apple handles the payment; we never see your card details or your Apple ID.

To know whether a subscription is active, the app asks RevenueCat (RevenueCat, Inc., United States) when it opens and when you buy. RevenueCat receives a random identifier created for this purpose, your app version and iOS version, the country of your App Store account, and, like any internet service, the IP address the request came from. If you buy, it also receives which product you bought, when, and the price and currency. It receives nothing you log in Tideline.

From version 1.0.2, at the end of setup, Tideline asks where you heard about it. The question is optional. If you answer, that one answer (for example “TikTok”) is sent to RevenueCat with the same random identifier, so we can count which places bring subscribers. It never includes anything you log, and you can skip it.

From version 1.0.7, while you set the app up for the first time, Tideline also tells RevenueCat the name of the furthest setup screen you reached, for example “cycle length” or “plans”, with the same random identifier. It is the name of a screen, never what you chose or typed on it, and it ends when setup ends: nothing is counted inside the app afterwards. We use it to see on which screen people give up, so we can make setup shorter. A phone whose App Store account is in the European Economic Area, the United Kingdom or Switzerland does not send it.

We use it because a subscription cannot work without checking that it was paid for (GDPR Art. 6(1)(b)). Transfers to the United States are covered by the standard contractual clauses in RevenueCat's data processing agreement. Their policy is at revenuecat.com/privacy.

App updates

From version 1.0.4, when the app opens it asks Expo (650 Industries, Inc., United States), the service that delivers Tideline's updates, whether newer app code is available, so fixes and improvements can reach you between App Store versions. The request carries your iOS version, the app version, a random identifier created for this installation, and, like any internet service, the IP address it came from. Expo uses the identifier to count how many installations check for updates. It contains nothing you log in Tideline.

We use it to keep the app working and to fix problems quickly (GDPR Art. 6(1)(f)). Expo's privacy policy is at expo.dev/privacy.

What Tideline does not do

• No advertising networks, no advertising or analytics kits from other companies, no tracking across apps or websites. The one thing the app itself counts is how far setup got, described under Purchases.
• No selling or renting of data. There is no data on our side to sell.
• No access to your contacts, location, photos or camera.

Apple gives every developer totals such as the number of downloads and sales per country, and crash reports if you agreed in iOS Settings to share them with developers. RevenueCat shows us the same kind of totals for subscriptions, such as how many trials began and how many were kept, and, from the optional question, which places they came from, which is why the App Store privacy label lists purchase history under analytics, and, from version 1.0.7, how far setup got, listed there as product interaction. None of this identifies you.

When you write to us

You can send us a message from inside the app: You → Tell Period what you think, or when Period asks whether anything is missing. Nothing is sent until you tap Send. Then the app sends what you typed in that box, the kind of message you picked, and your app version and iOS version to RevenueCat, the service described under Purchases, with the same random identifier and, like any internet service, the IP address the request came from. We read it there. It carries no name and no address unless you type one, and it never includes anything you log. Please leave out anything medical; we never need it to help you.

We use a message to improve the app and, if you gave an address, to answer you (GDPR Art. 6(1)(f)). Anything about your health that you choose to write in it, we read only because you sent it to us (Art. 9(2)(a)). To have a message deleted, email us what it said and roughly when you sent it, and we delete it at RevenueCat.

If you email us, we receive your address and what you wrote. We use it to answer you and delete the conversation when you ask.

Deleting your data

In the app, You → Delete everything erases every entry, your cycle and your settings from the phone at once. Deleting the app does the same. Deleting the app does not cancel a subscription; you cancel that in iOS Settings → your name → Subscriptions.

To have your purchase record removed from RevenueCat, email us the order number from Apple's receipt and we will have it deleted.

Your rights

Depending on where you live (for example under the GDPR or the CCPA) you can ask for access to your data, a copy of it, correction or deletion. Because your record is only on your phone, those are already in your hands: the export is free and deletion is one tap. For the purchase record, or for anything else, write to us. You also have the right to complain to your data protection authority.

Our consumer health data privacy policy sets out the same facts in the form Washington, Nevada and Connecticut ask for, with how to use your rights there.

Children

Tideline is not meant for children under 13, and we do not knowingly collect information from them: what is logged stays on the phone it was logged on.

Changes

If this policy changes, this page and its date change with it, and a change that matters is mentioned in the app's release notes.