Terms of use
Last updated 21 September 2026
The short version. Tideline is a personal record, not a medical device. Logging, your history and the export are free. Tideline Plus is a subscription you can cancel at any time in your iPhone's settings.
1. What Tideline is, and what it is not
Tideline helps you keep a dated record of your cycle, your mood and your symptoms, and turns that record into a summary you can show a doctor. It does not diagnose, treat, cure or prevent any condition, and it does not replace a doctor. Only a clinician can tell you whether you have PMDD or anything else.
The cycle dates the app shows are estimates worked out from what you entered. They can be wrong. Tideline is not birth control and must not be used to avoid or plan a pregnancy.
The tips in the app are everyday ideas, not medical advice. Talk to a doctor before changing any medication.
If you are thinking about harming yourself, do not wait for an app. Call your local emergency number or a crisis line now.
2. Your record
Your record is stored only on your phone (see the privacy policy). That means we cannot restore it for you. It moves to a new iPhone with your normal iPhone backup, and you can export it at any time for free.
3. Tideline Plus
Free: logging, your calendar and history, the export, reminders, the Apple Health import, two tips a day, some of the articles, and your partner seeing where you are in your cycle. Tideline Plus adds the tips chosen from what you log, what to expect each day, your hormone pattern, the doctor's report as a PDF, every article, and the heads-up for your partner with your notes on what helps.
- Plus is an auto-renewing subscription, monthly or yearly. The price is shown in the app before you buy, in your currency.
- Payment is charged to your Apple ID when you confirm. The subscription renews for the same period unless you cancel at least 24 hours before the current period ends.
- If you choose the free month, you pay nothing today. When the month ends the yearly price is charged, unless you cancel at least 24 hours before. The app shows you the date before you agree, and reminds you two days ahead if notifications are allowed.
- You manage and cancel in iOS Settings → your name → Subscriptions. Deleting the app does not cancel.
- Refunds are handled by Apple at reportaproblem.apple.com.
When a subscription ends, nothing you logged is locked or deleted. You keep your record and the free features.
4. Sharing with a partner
You decide who receives your link. Anyone who has the link can see what it holds until it runs out after 45 days, so send it only to someone you trust.
5. Fair use
Tideline is licensed to you for personal, non-commercial use. Please do not copy, resell or take the app apart, except where the law allows it.
6. Apple's licence
Apple's standard licence agreement for apps (EULA) applies together with these terms. Where the two differ, these terms apply to the points they cover.
7. Liability
We build Tideline with care, but it is provided as it is, and we cannot promise it will be free of errors or always available. To the extent the law allows, we are not liable for decisions made on the basis of the app's estimates or for the loss of a record that was stored only on your device. Nothing in these terms limits liability that cannot be limited by law, or the rights you have as a consumer in the country where you live.
8. Changes
If these terms change, this page and its date change with them. A change never takes away something you have already paid for during the period you paid for.