Delta Privacy Policy

Last updated 2026-07-07

The short version: Delta has no account, no servers, and collects nothing. Your data lives on your device and, if you turn on iCloud, in your private iCloud. We never see it, never transmit it to ourselves, never sell it, and show no ads.

Delta is a personal workout notebook. It was built specifically to avoid the things most fitness apps do, so this policy is short because there is very little to say.

What Delta stores, and where

• On your device. Your workouts, check-ins, routines, and settings are stored locally on your iPhone (and Apple Watch).
• In your private iCloud (optional). If iCloud is enabled, that same data syncs across your Apple devices through Apple's private CloudKit database, tied to your Apple Account. This sync is between you and Apple. The developer of Delta has no access to it and cannot read it.
• Nowhere else. Delta has no account system, no login, and no servers of its own. Your data is never uploaded to the developer or to any third party.

What we collect

Nothing. Delta contains no analytics, no advertising, no tracking, and no third-party SDKs that phone home. We do not build a profile of you, because we receive no data about you at all.

The same goes for this website: no analytics, no cookies. If you pick a theme color on the homepage, that one word is saved in your browser's local storage on your device so the site remembers your pick. It is never transmitted anywhere, and clearing your browser data removes it.

Apple Health (HealthKit)

If you grant permission, Delta reads the following from Apple Health to show real effort and readiness alongside your logged workouts:

• Heart rate and active energy (effort per workout, and heart-rate zones)
• Resting heart rate, date of birth and biological sex (to estimate heart-rate zones and to place a VO₂ max reading in its age and sex band)
• Heart-rate variability and VO₂ max (Apple's own estimates, shown as measured, never recalculated by Delta)
• Sleep analysis (to show measured sleep next to your check-ins)
• Workouts and their GPS routes (to import cardio you recorded elsewhere, and to draw the map for a run you already had in Health)

Delta writes back:

• The strength and cardio workouts you record on Apple Watch, along with their heart rate, active energy, distance and GPS route
• The body weight you enter at a check-in, so a weigh-in logged in Delta is visible to any other app you have chosen to trust. Apple Health is the account-free way apps pass data to each other, which is what lets Delta stay account-free. Declining this costs you nothing but the hand-off: the check-in still saves in Delta.

Delta never writes data you did not create.

All Health data is read and used on your device only. It is never transmitted to the developer or anyone else, and is never used for advertising or sold. You can revoke access at any time in Settings → Privacy & Security → Health.

Location

During an outdoor run, walk or ride, Delta uses GPS to measure your distance, pace and route, and to recognise a route you have run before. Location is used only while a cardio workout is running, never in the background and never when the app is closed.

Your route is stored on your device and in your own iCloud with the rest of your history, and written to Apple Health alongside the workout. It is never transmitted to the developer, and there is no server to transmit it to. You can revoke location access at any time in Settings → Privacy & Security → Location Services.

Your data is yours

• Export anytime. Delta exports your full history to a CSV file you control.
• Delete anytime. Deleting the app removes its local data; you can also wipe all data inside the app. Data in your iCloud is governed by your Apple Account.
• No lock-in. Because everything works offline and exports cleanly, you are never dependent on the developer continuing to run a service.

Children

Delta is not directed at children and does not knowingly collect any information from anyone, including children.

Changes to this policy

If this policy ever changes, the updated version will be posted here with a new date. Because Delta collects nothing, any change can only ever narrow what is already none.

Contact

Questions about privacy: support@deltastrength.app

Delta is an independent app from Lesko Technology Solutions LLC.
No account. We don't want your data. This is your notebook.