All apps
For interval training

SQNZ

Interval timer for iPhone and Apple Watch.

You set work and rest, the app counts down for you. For HIIT, Tabata, circuits and boxing rounds. No account. Timers run without an internet connection.

iPhoneApple Watch · Premium

For iPhone 11 or later and iPhone SE (2nd generation) or later. On Apple Watch from Series 6, SE (2nd generation) and every Ultra, together with SQNZ Premium on your iPhone. · FAQ

Coming soon

SQNZ Privacy Policy

Last updated: September 23, 2026

Overview

SQNZ is an interval timer for iPhone and Apple Watch. This policy explains what data is processed, on what legal basis, how long it is kept, and what rights you have. The short version: the app itself sends nothing to any server.

Do You Have to Provide Anything?

No. SQNZ has no account, no registration, no login and no required field. You are not asked for a name, an email address or a date of birth, and nothing you leave empty stops the app from working. Everything you create — timers, flows, statistics — you create because you want to, and it stays on your device. The only two features that ask you for anything are optional and named below: saving to Apple Health, and the AI import.

Data Stored on Your Device

  • Timer configurations — your created timers, flows, and settings
  • Workout statistics — session history, streaks, and duration
  • App preferences — settings, language, and sound

Data We Do Not Collect

  • No personal data (name, email, address)
  • No location tracking
  • No analytics or tracking SDKs
  • No microphone or voice recordings
  • No cloud sync of our own — the app transfers nothing by itself
  • No selling or sharing of data

No External Data Processors

SQNZ engages no external data processors acting on its behalf: the app itself transmits no timer, workout, or preference data to any server and uses no analytics or tracking SDKs — everything you create stays on your device. The only data flows that exist are operated by Apple as an independent controller (app distribution, in-app purchases, and optional system crash reports) and are described in the sections below.

Apple Watch Sync

If you pair SQNZ with an Apple Watch, your timers, favorites and workout statistics sync between iPhone and the paired Watch via Apple's WatchConnectivity framework. The transfer is local (Bluetooth / direct radio) — no data is stored on Apple servers beyond the temporary delivery buffer the system uses. Legal basis: Art. 6(1)(b) GDPR (contract — expected feature).

Apple Health (optional)

SQNZ can, if you choose, save completed timer sessions to Apple Health on your device: as a workout (activity type, start, end, duration). You choose for each timer whether and in which category it is saved; timers without a Health category and sessions shorter than one minute are never saved. This feature is off by default.

  • SQNZ does not read any data from Apple Health and does not display any health data.
  • The data written stays in Apple Health on your device. SQNZ never transmits it anywhere — not to us, not to third parties, not to any server; we have no access at any time. No analysis, no advertising, no profiling.
  • Entries written by SQNZ remain in Apple Health — even after you uninstall the app — until you delete them there. You control the retention period yourself.
  • The entries written are health data (special category, Art. 9(1) GDPR). Data is saved only if you actively turn the feature on and give your explicit consent in the Apple Health system dialog (Art. 9(2)(a) in conjunction with Art. 6(1)(a) GDPR). Voluntary — the timer and all other features work fully without it.
  • Withdraw at any time with effect for the future: turn the feature off in SQNZ settings or revoke the permission under "Settings → Privacy & Security → Health → SQNZ". You can remove entries already stored in Apple Health, or via SQNZ ("delete all sessions saved by SQNZ", while write permission still exists). The lawfulness of processing carried out before withdrawal remains unaffected.
  • Apple Health may synchronise your data across devices via iCloud — in that case it travels to Apple's servers. This is an Apple system service that you turn on or off yourself in iOS and that Apple is responsible for.
  • Since we receive no copy of this data, you exercise your rights to it directly via Apple Health. Your other rights (access, complaint to the LDI NRW, etc.): see the "Your Rights (GDPR)" section. The controller is named in the "Controller / Responsible Person" section.

Workout Sessions on Apple Watch (optional)

When you start a timer on your Apple Watch that is set to a sport Health category and have Apple Health saving enabled, SQNZ starts a workout session on the Watch. This is what allows the Watch to alert you with a haptic tap while your wrist is lowered — without a workout session, watchOS suppresses those taps entirely. Whether a timer counts as a sport timer is determined by the Health category you have assigned to it (see previous section). Timers without a sport Health category — learning timers, for example — never start a workout session.

  • While a workout session runs, your Apple Watch records heart rate and active energy on its own and saves them to Apple Health on your device. This recording is performed by watchOS, not by SQNZ — but it happens because SQNZ starts the session, so we name it here.
  • SQNZ has no access to these values. We request no read permission of any kind, we run no queries, and we never receive, store or transmit heart rate or energy data. Our statement above stands unchanged: SQNZ does not read any data from Apple Health.
  • The recorded data stays in Apple Health on your device, under your control. There are no recipients on our side — not us, not third parties, no server of ours. Apple Health's optional iCloud sync described in the previous section applies to this data in the same way.
  • This data is health data (special category, Art. 9(1) GDPR). It is recorded only if you have actively enabled Apple Health saving in SQNZ — the notice you confirm when turning it on describes this recording — and allowed workout saving in the Apple Health system dialog (Art. 9(2)(a) in conjunction with Art. 6(1)(a) GDPR). Voluntary — the timer and all other features work fully without it.
  • Withdraw at any time with effect for the future: turn Apple Health saving off in SQNZ settings, or revoke the permission under "Settings → Privacy & Security → Health → SQNZ". No further workout session will be started. Heart rate and energy entries already recorded by watchOS can be deleted directly in Apple Health; because SQNZ did not write them, SQNZ's "delete all sessions saved by SQNZ" function does not remove them. The lawfulness of processing carried out before withdrawal remains unaffected.
  • Your Watch also counts this activity toward your Activity Rings. That is a system function of watchOS, not a feature of SQNZ.

Phone Call Detection (iPhone & Apple Watch)

The app observes whether a phone call is currently active via Apple's CallKit framework, so a running timer can auto-pause when you take a call. No call metadata (caller, number, duration) is read, stored, transmitted or logged — only the on/off signal is held in memory for the duration of the running timer. Legal basis: Art. 6(1)(b) GDPR (contract — expected feature). You can disable this in Settings → Timer Behavior → Pause on interruption.

Notifications

SQNZ uses local notifications on iPhone and Apple Watch to alert you when a timer ends, even if the screen is off or the app is in the background. iOS asks for your permission once (on iPhone, the first time you start a timer), and you can change this anytime in iOS Settings. No push tokens are registered with any remote server; all notifications are scheduled locally on your device. Legal basis: Art. 6(1)(b) GDPR (contract — expected feature), and your permission in the iOS system dialog.

Voice Announcements

Spoken phase names and countdowns use Apple's on-device speech synthesis (AVSpeechSynthesizer). No audio is recorded, transmitted, or sent to Apple servers. Premium / Enhanced voices that you may have installed via iOS Settings → Accessibility → Spoken Content remain entirely on your device. If you choose the optional AI voice (Supertonic 3) instead, the announcements are generated by an AI model that ships inside the app and runs only on your iPhone. The generated clips are stored in the app's cache on your device, carry a machine-readable marking that they are AI-generated, and are never transmitted. SQNZ records locally which version of the AI voice rules of use you accepted.

iCloud Backup

SQNZ stores its data in the standard iOS app sandbox. If you have iCloud Device Backup enabled in iOS Settings, your timer configurations and workout statistics may be included in that backup. Apple encrypts iCloud backups end-to-end when Advanced Data Protection is on. The app itself does not write to iCloud — there is no proprietary cloud sync.

In-App Purchases

SQNZ offers one optional in-app purchase, the Premium unlock. It is a one-time purchase, handled entirely through Apple's App Store and StoreKit. SQNZ has no access to your payment information, sees no name, no card and no Apple ID, and stores nothing about the transaction. What the app does keep is a single yes/no flag recording that Premium is unlocked, so the unlock is not lost. Where that flag is stored, and how long it stays, is described under "Storage Duration". Payment data is processed by Apple as an independent controller. Legal basis: Art. 6(1)(b) GDPR (contract).

Creating a Timer with an AI App

The import uses no AI of its own and makes no request to any AI service. What the import does is this: it takes the description you typed, wraps it in a prepared instruction that asks for our timer format, copies the whole thing to your clipboard, and opens the AI app you picked — ChatGPT or Claude, or their website if the app is not installed. From that point on you are in someone else's app, under your own account. Your description and anything the AI writes back are processed there under that provider's privacy policy and terms, not ours. We never see the exchange. When you paste the answer back into SQNZ, it becomes a timer on your device like any other. If you would rather not use this, you do not have to: every timer can be built by hand, and the app is fully usable without the import.

Records of Your Consent

Where the app asks you to confirm something, it notes on the device that you did, with the date and which version of the text you saw. This applies to the Apple Health notice, the health disclaimer before your first timer, and the hearing-protection warning. We are required to be able to show that consent was given (Art. 7(1) GDPR), and these notes are how the app does that. They stay on your device; we never see them and they are never transmitted. Two of them are cleared when you reset the app; the hearing-protection one is described under "Your Rights (GDPR)". Legal basis: Art. 6(1)(c) GDPR (legal obligation).

Distribution and Apple

SQNZ is distributed through Apple's App Store. Apple may collect diagnostic, usage, and download metadata independently from this app under Apple's own privacy policy (https://www.apple.com/legal/privacy/). SQNZ has no access to that data and is not the controller in this respect.

System Crash Reports

iOS itself may collect crash reports and share them with Apple and with us, the developer, via App Store Connect. This is a system-level process — SQNZ does not implement its own crash reporting, and we receive nothing unless you have allowed it in iOS. You can turn it off at any time under iOS Settings → Privacy & Security → Analytics & Improvements → Share with App Developers. What we see is technical: the version, the device model, and where in the code the app stopped. Reports contain nothing you entered in SQNZ — no timers, no statistics, no health data — and we use them only to fix crashes. Apple decides what these reports contain and is the controller for collecting them.

International Data Transfers

The app itself transfers nothing to a third country. The only transfers that exist are Apple's own, and SQNZ is not involved in them. Apple Inc. is based in the United States. According to Apple's own privacy policy (as of 14 September 2026), transfers of personal data collected in the European Economic Area, the United Kingdom and Switzerland are governed by the EU Standard Contractual Clauses (Art. 46(2)(c) GDPR, Implementing Decision (EU) 2021/914). Apple provides a copy of those clauses on request. Since SQNZ has no access to that data flow, Apple acts as an independent controller under its own privacy policy.

Storage Duration

Your data remains on your device until you delete it manually or uninstall the app. There is no automatic expiry, and nothing is ever sent off-device by the app. Two entries are the exception, because they live in this device's keychain and survive an uninstall: the record that you acknowledged the hearing-protection warning, and the flag that Premium is unlocked. Both are described under "Your Rights (GDPR)". Neither is synced to iCloud. Statistics, timers and flows accumulate over time and stay on the device.

Your Rights (GDPR)

Under Art. 15–22 GDPR you have the right to access, rectify, erase and restrict the processing of your personal data, and to receive it in a portable form. Because everything stays on your device, you exercise most of these rights directly in the app. Timers, flows and workout history are deleted under Settings → Data ("Delete all timers", "Delete all flows", "Clear workout history"), and any timer can be exported as a file to take with you. Uninstalling removes the app's entire sandbox.

Two entries sit outside it, in this device's keychain, and both survive an uninstall. Neither ever leaves this device — they are not synced to iCloud.

1. The record, with its date, that you acknowledged the hearing-protection warning. It is kept on purpose so the acknowledgement is not lost, and it is erased by "Reset settings to defaults" under Settings → Data.

2. A yes/no flag that Premium is unlocked, kept so a purchase you paid for is not lost. This flag has no delete button in the app today; write to us and we will tell you how to remove it.

For questions, and for any request under these rights, contact support@casystudio.com.

Right to Object & Complaint

Art. 21 GDPR — Right to object: you may object at any time to any processing based on legitimate interests. SQNZ does not process data on that legal basis, but the right is named here for completeness. Art. 77 GDPR — Right to lodge a complaint: you may complain to a supervisory authority, in particular in the EU Member State of your habitual residence, place of work, or place of the alleged infringement. The authority competent for the controller is:

Landesbeauftragte für Datenschutz und Informationsfreiheit Nordrhein-Westfalen (LDI NRW)

Kavalleriestraße 2–4, 40213 Düsseldorf, Germany

Automated Decision-Making

There is none. SQNZ makes no automated decisions about you within the meaning of Art. 22 GDPR and does no profiling. The app counts down, keeps a history of what you finished, and shows you streaks. It draws no conclusions about you from that, and nothing it shows has any legal or similarly significant effect.

Children

SQNZ is not directed at children. It asks for no age and has no way to verify one, because it has no account and collects nothing about you. Our Terms of Use ask that you be at least 13 years old to use the app. The Apple Health feature is the one part of SQNZ that processes health data, and it is off by default and requires an explicit decision to turn on. If you are a parent and want the app used without it, leave that switch off.

Controller / Responsible Person

The controller for data processing under Art. 4(7) GDPR, as far as the GDPR applies to the use of this app:

Adriano Camonita

Barthstr. 6

44328 Dortmund

Germany

Email: support@casystudio.com

We have not appointed a data protection officer. We are not required to: SQNZ processes no personal data on our side, we run no servers, and our size is far below the thresholds of Art. 37 GDPR. Send anything about data protection to the address above.

Changes to This Policy

We update this policy when the app changes what it does with data — a new feature, a new permission, a different way of storing something. The date at the top always says when it was last changed. If a change affects a consent you have already given, the app asks you again rather than relying on the old one. The current version is always the one in the app and on our website; there is no archive of older versions.