Privacy Policy
Last updated: 3 October 2026
SlumberBrew keeps your health, drink, sleep, symptom and rating data on your device. You can export a backup file and save it wherever you choose. SlumberBrew never uploads your data to iCloud or any server. There is no SlumberBrew account and no SlumberBrew server holding your app content. The configured 1.0 app makes one narrow network exception: Apple and RevenueCat handle subscription status and purchases. RevenueCat receives the purchase record and the technical transaction information needed to keep Pro working; it does not receive your app content.
This policy covers both the iPhone app and the website at slumberbrew.com, including the free web tracker.
The website
The web tracker at slumberbrew.com stores what you log in your browser's local storage. It is not sent anywhere. There is no account, and we have no way to see it.
Clearing your browser data removes it, and so does the "Delete everything" button on the tracker's Settings tab. Local storage is per-browser and per-device, so what you log on your laptop will not appear on your phone.
The site has no analytics, no cookies, no tracking pixels and no advertising. It sets no cookies at all. Pages are static files and nothing you do on them is logged by us.
Whoever hosts the site will keep standard server logs, which typically include IP addresses and are used to serve the site and defend it from abuse. We do not use those logs to build any profile of you.
Who we are
SlumberBrew is made by Cael Jones, a sole developer based in the United Kingdom. For anything in this policy, contact cmjonesapps90@gmail.com.
What the app stores, and where
Your records live in a shared container on your device. These include:
| What | Where it lives | What's in it |
|---|---|---|
| Your drink log | log.json | Every drink you've logged: name, caffeine in mg, and the time you had it |
| Your sleep ratings | ratings.json | The 1 to 5 rating you give a night, and how long it felt like it took to drop off |
| How you felt | symptoms.json | Symptoms you log — headache, tiredness, jitters and the rest — with the time and how bad you said it was |
| Your day ratings | feelings.json | The 1 to 5 rating you give a day |
| Skipped nights | skipped-nights.json | Nights you chose not to rate, so the prompt does not ask again |
| Your settings | settings.json | Bedtime, wake time, half-life, targets, quick-add drinks, custom drinks, theme |
| App bookkeeping | a few small files | Which logged drinks have already been written to Apple Health, whether you have been asked to connect it, recent Siri suggestions, and which screen a widget or notification should open. No health readings |
The container is shared between the app and its home screen widget, which is how tapping a drink on the widget updates the number in the app. It is not shared with anything else. If you choose Back up & restore or Export your data, the app encodes these records as a portable file and hands it to you to save wherever you choose. SlumberBrew does not upload it anywhere, and we never receive it.
If you have iCloud Backup switched on, iOS may include this container in your device backup, as it does for most apps. That is Apple's whole-device backup, which you control in iOS Settings; SlumberBrew does not upload anything to it. We can't see it, and we can't restore from it.
Backup files
Settings › Data › Back up & restore and Export your data create a JSON file of your drinks, sleep ratings and sleep times, symptoms, day ratings, skipped nights, custom drinks and preferences. The file is handed to you to save wherever you choose; SlumberBrew does not upload it and we never receive it. It does not include purchases or your Apple Health library. Restoring adds missing records and keeps existing ones, so restoring the same file twice does not duplicate anything.
Apple Health
If you connect Apple Health, two things happen, both of which you control. A third is optional and off unless you turn it on.
SlumberBrew reads your sleep. It looks at up to the last 90 days of sleep analysis so it can show you how caffeine at bedtime lines up with how you actually slept. That data is read on your device, used on your device, and never sent anywhere by SlumberBrew. SlumberBrew never uploads it to iCloud. If you save a backup file, the sleep times on the nights you rated are included in the file you save.
SlumberBrew can write the drinks you log back to Health as dietary caffeine, so the rest of your health record stays complete. It never reads any health data other than sleep.
If you turn on Save symptoms to Health, SlumberBrew writes symptoms you log as the matching Apple Health types: headache, fatigue, mood changes and nausea. Symptoms with no matching Health type stay in SlumberBrew. Ending or deleting a symptom updates the copy in Health. This is off by default, iOS asks your permission before anything is written, and you can turn it off in Settings.
You can turn either direction off at any time in the iOS Settings app under Privacy & Security › Health › SlumberBrew. Health data is never used for advertising, never sold, never shared with anyone and never uploaded to iCloud by SlumberBrew. SlumberBrew writes nothing else to Health.
If you want to remove caffeine or symptoms SlumberBrew has already written to Health, you can do it in the Health app under Browse › Nutrition › Caffeine and Browse › Symptoms.
How you feel
You can log symptoms — a headache, tiredness, jitters — and rate how a day went. SlumberBrew compares those against what you drank, so it can show you what cutting down looks like in your own log and how long it lasts.
This is health information about you, and it is treated exactly like the rest: it is written to a file on your device, it is never sent anywhere, there is no account attached to it, and it is included only in backup files you choose to save. It is never read from Apple Health, and it is written there only if you turn on Save symptoms to Health (see above). “Delete everything” in Settings removes it along with the rest, and so does deleting the app. Neither removes a backup file you saved elsewhere.
None of it is a medical assessment. The app compares your own days against each other and nothing more. It does not know about anything else going on with you, and it cannot rule anything out.
Notifications
The caffeine curfew alert and the morning sleep check are scheduled on your device by iOS. They are not push notifications. Nothing is sent to a server to make them happen, and no one else knows when they fire.
What we collect about you
The configured 1.0 app does not send your health, drink, sleep, symptom or day-rating data anywhere. It has no analytics SDK, no crash reporting, no advertising identifiers, and no tracking of any kind. It does not ask for the App Tracking Transparency permission because there is nothing to track.
For subscription functionality, RevenueCat receives Purchase History: the Apple purchase receipt, an anonymous app user ID and the technical transaction information needed to validate purchases, keep entitlements current and provide subscription reporting. This data is not linked to your identity and is not used for tracking. Apple handles your payment details. RevenueCat does not receive your drink log, sleep data, symptoms or ratings.
The app contains links to the research it cites. Tapping one opens your browser and takes you to a publisher's website, at which point their privacy policy applies, not ours.
Analytics (if enabled in a future version)
This section applies from the version in which product analytics ship. It does not apply to version 1.0.
We use PostHog, hosted in the European Union, to understand how the app is used: which features people reach, where they get stuck, and whether the widget actually gets used. Events record counts and actions, never content.
We do not send PostHog your caffeine amounts, your drink times, your sleep ratings, your bedtime, or anything read from Apple Health. Backup files you export are separate from analytics and are never sent to us.
PostHog processes this on our behalf as a data processor. Their privacy information is at posthog.com/privacy.
Purchases
This section applies to the configured 1.0 app.
Purchases are handled by Apple. We use RevenueCat to check whether a subscription is active. RevenueCat receives the Apple purchase receipt, an anonymous app user ID and the technical transaction information required to validate and report subscription status. It does not receive your name, your email, custom user ID, advertising identifier or any data from the app's drink log, sleep data or ratings. Apple handles your payment details and never shares them with us. RevenueCat's privacy policy is at revenuecat.com/privacy.
Your rights
Because your app content is either local or in a private backup you control, most data rights are things you can exercise yourself, immediately, without asking us. Apple and RevenueCat keep purchase records needed for the subscription service; deleting local app data does not delete those store records or your separate backup copies.
- Access and portability. Settings › Data › Export your data writes everything the app holds to a JSON file you can save or send wherever you like.
- Erasure. Settings › Data › Delete everything removes your local log, ratings, symptoms, day ratings, skipped nights and settings, and returns the app to a fresh install. Deleting the app does the same thing locally. Files you saved are separate copies and can be deleted from wherever you put them. On the website, the Settings tab of the tracker has the same button, and clearing your browser data also works.
- Rectification. You can edit or delete any individual entry in either version.
If you're in the UK or the EU and you believe we've mishandled your data, you can complain to your national supervisory authority. In the UK that's the Information Commissioner's Office at ico.org.uk.
Children
SlumberBrew isn't aimed at children and we don't knowingly collect personal data from children. Caffeine guidance for adults doesn't transfer to children, and the app says so where it matters.
Changes to this policy
If this policy changes in a way that affects what happens to your data, the change will be described in the app's release notes rather than quietly published here. The date at the top always reflects the current version.
Contact
cmjonesapps90@gmail.com