In short
- Kilter has no accounts. Your check-ins, notes and history stay on your iPhone.
- Kilter reads Apple Health only with your permission, and never sells or shares your data for advertising.
- If you turn on AI insights, a summary of your recent days is sent through Kilter's server to OpenAI to write your reads and weekly summary. Your name, your notes and your raw Health samples are never sent.
- There are no trackers, adverts or third-party analytics. With AI insights on, Kilter's server counts how many devices use Kilter each day, without any health data.
About this policy
This policy explains how Kilter ("Kilter", "we", "us") handles information when you use the Kilter app for iPhone. Kilter is made by Cosy Apps Lab Ltd, an independent app studio based in the United Kingdom, which is the data controller for the limited data described here.
What stays on your iPhone
Almost everything Kilter knows about you is kept only on your device, in the app's own storage:
- your morning check-ins, feelings through the day, energy and stress ratings;
- caffeine and alcohol you note, aches you flag, and any day notes you write;
- your goals, preferences, reflections and feedback on reads;
- the patterns and baselines Kilter works out from your data.
We have no copy of this. It is included in your iPhone or iCloud backups in the same way as other app data, under Apple's protection.
Apple Health
With your permission, Kilter reads sleep, steps, active energy, exercise minutes, heart rate, resting heart rate, heart rate variability and workouts from Apple Health, to describe your nights and days and learn your usual rhythm.
Kilter writes one thing to Apple Health: each morning check-in, saved as a State of Mind entry, if you allow it.
Health data is never used for advertising or marketing, never sold, and never shared with data brokers. You can change what Kilter can read or write at any time in Settings > Health > Data Access & Devices > Kilter.
AI insights (optional)
With AI insights, Kilter can write fuller personal reads about your sleep, movement and recovery, and a weekly summary. When this is turned on, the app sends a summary of your recent days to our server, which passes it to OpenAI to write the read. The summary can include:
- daily totals and averages, such as hours asleep, bedtime, wake time, steps, active minutes and heart rate;
- your check-in answers, the timing of caffeine and alcohol, and body areas you have flagged as aching;
- your goals, feedback on earlier reads, and general weather conditions (not your location);
- your time zone.
It never includes your name, contact details, day notes, precise location or raw Health samples.
Our server runs on Cloudflare. It checks that each request comes from the genuine Kilter app on a real Apple device, using Apple's App Attest, and then forwards it. It does not store the content of your requests or the reads. It keeps only an anonymous key for your device and a daily count of requests, used to prevent misuse. Daily counts expire automatically.
So we can see whether people come back to Kilter, the server also notes, under a pseudonymous device number, the first day a device used AI insights and the days it was active since. These counts contain no health data, and the per-device record expires after six months.
When you rate a read or send a note from the You tab, the rating, the wording of that read and your note are kept by us for up to a year, under the same pseudonymous device number, to improve future reads.
OpenAI processes the summary to write the read. We ask OpenAI not to store it, and under OpenAI's API terms it is not used to train their models. OpenAI may keep requests for a limited period, currently up to 30 days, to monitor for abuse, and then deletes them. See OpenAI's API data usage policies.
You can turn AI insights off at any time in the You tab. Kilter then writes its reads on your iPhone instead, and nothing is sent.
Morning reminder
If you turn on the morning check-in reminder, Kilter schedules it on your iPhone. Nothing is sent to us or anyone else to do this, and you can turn it off in the You tab or in Settings > Notifications.
Location and weather
If you allow it, Kilter uses your approximate location, never your precise one, to fetch local weather from Apple's WeatherKit: overnight temperature and humidity for sleep, and pleasant windows for movement. The location is rounded before it is stored on your device, and it is shared only with Apple to get the forecast. Weather data is provided by Apple Weather. You can turn location off in Settings > Privacy & Security > Location Services.
Motion
Kilter uses your iPhone's tilt to move the balance illustration gently. Motion data is used in the moment only and is never stored or sent anywhere.
What we don't do
- No accounts, sign-in or email collection.
- No advertising, tracking or third-party SDKs, and no analytics beyond the daily counts described above.
- No selling or renting of any data, ever.
- Kilter is not a medical device and does not diagnose, treat or give medical advice.
Beta testing through TestFlight
If you test Kilter through Apple's TestFlight, Apple shares some information with us, such as crash reports, the device model and any feedback or screenshots you choose to send. If you joined by email invitation, Apple also shares your name and email address with us. This is handled under Apple's Privacy Policy, and we use it only to improve the app.
Legal basis and your rights
Health information is special category data. We process it only with your explicit consent, which you give through Apple's Health permissions and the AI insights setting, and which you can withdraw at any time by changing those settings.
Under UK and EU data protection law you can ask to access, correct or delete your information, object to its use, or withdraw consent. Because Kilter keeps your data on your device, you can do most of this yourself:
- Delete everything Kilter stores: in the You tab, choose Delete my data. This clears Kilter on your iPhone and asks our server to delete your ratings, notes and activity record. Deleting the app also removes everything on your iPhone.
- Delete check-ins saved to Health: use the Health app (Browse > Mental Wellbeing > State of Mind).
- Stop data leaving your phone: turn off AI insights in the You tab.
For anything else, contact us using the details below. You also have the right to complain to the Information Commissioner's Office.
Children
Kilter is not intended for anyone under 16, and we do not knowingly process data from children.
Changes to this policy
If this policy changes, we will update the date at the top of this page. If a change affects how your data is shared, we will tell you in the app before it takes effect.
Contact
Questions about privacy? Email hello@cosyappslab.com.