We built IntervalSync to keep your data on your device and within your personal Apple ecosystem wherever possible. We do not sell your data, we do not use it for advertising, and we collect as little as possible.
Summary
- Your workouts are stored on your device and, if you enable it, backed up to your private iCloud account — not to us.
- Health data (heart rate, distance, completed workouts, and recorded outdoor workout routes) is read and written through Apple Health on your Apple Watch during workouts. It stays on your device / in Apple Health. We never receive it.
- Location is used during outdoor workouts, entirely on-device, to record your route in Apple Health and, when you assign a GPX route, show your route progress. We never receive it.
- Voice input is optional. If you use it, your speech is processed for transcription and is not stored by us.
- The only information that reaches our servers is feedback you choose to submit, which we use to improve the workout parser.
- We do not show ads, and we do not sell or share your personal data with advertisers or data brokers.
Information the App handles
1. Workout data you create
When you create or edit a workout, the App stores it locally on your device using Apple's on-device storage (SwiftData). This includes the workout name, your typed or spoken description, intervals, distances, durations, and pace targets.
2. iCloud backup (optional)
If you enable Backup to iCloud in Settings, your workouts are synced to your own private iCloud account via Apple's CloudKit. This data is governed by Apple's iCloud terms and Privacy Policy. We do not have access to your iCloud data and cannot read it. You can turn this off at any time in Settings.
3. Health & fitness data (HealthKit)
On Apple Watch, IntervalSync uses Apple HealthKit to:
- Read your heart rate and distance during a workout so the App can display live metrics.
- Write completed workouts and recorded outdoor workout routes to Apple Health so your activity is recorded alongside your other health data.
We make the following commitments regarding HealthKit data:
- HealthKit data is processed on your device and stored in Apple Health. It is never transmitted to our servers or to any third party.
- We do not use HealthKit data for advertising, marketing, or any use-based data mining.
- We do not sell or disclose HealthKit data to third parties.
You control HealthKit permissions in iOS/watchOS Settings → Health, and you can revoke them at any time.
4. Voice input (Speech Recognition & Microphone)
If you choose to describe a workout by voice, the App uses the microphone to capture your speech and Apple's Speech Recognition to transcribe it into text. To perform transcription, audio and/or transcripts may be processed by Apple in accordance with Apple's Privacy Policy. We do not store your recordings, and microphone access is used only while you are actively dictating a workout. Voice input is entirely optional — you can always type instead.
5. Sending workouts to your Apple Watch
Workouts you send from iPhone to your paired Apple Watch are transferred directly between your own devices using Apple's WatchConnectivity and scheduled through Apple's Workout framework. This transfer stays within your personal Apple ecosystem.
6. Routes & location (GPX)
You can import GPX route files into the App's route library and assign them to workouts. Imported route files are stored locally on your device.
If you start an outdoor workout, the Apple Watch app uses your location during that workout to record your route into Apple Health as a workout route. If the workout also has an assigned GPX route, location is also used to show your progress along the route, the bearing to the next point, and off-route feedback. Location is processed on your device in real time and is never transmitted to our servers or to any third party. Recorded workout routes stay in Apple Health unless you choose to export/share them yourself. Location access is used only during outdoor workouts, and you control the permission in watchOS Settings → Privacy & Security → Location Services.
7. Feedback you submit
If you submit feedback (for example, to report how a workout description was interpreted), the content of that feedback — which may include the workout text you entered — is sent to our backend, hosted on Google Firebase, so we can improve the App's natural-language parser. Submitting feedback is optional and only happens when you actively choose to send it. Firebase processes this data on our behalf; see Google's Privacy Policy.
What we do not do
- We do not display advertising.
- We do not sell, rent, or trade your personal information.
- We do not use third-party analytics or tracking SDKs to profile you.
- We do not require you to create an account or provide your name, email, or contact details to use the App.
How long we keep data
- Workout and Health data remain on your device (and in your iCloud, if enabled) until you delete them. You can erase all local app data from the in-app database reset option, and remove Health data via Apple Health.
- Feedback you submit is retained only as long as needed to improve the App, after which it is deleted or anonymised.
Children's privacy
IntervalSync is not directed at children under 16 and we do not knowingly collect personal information from children.
Your rights
Depending on where you live, you may have rights under data protection laws such as the UK GDPR / Data Protection Act 2018 and the EU GDPR, including the right to access, correct, or delete personal data we hold about you, and to object to or restrict certain processing. Because the only personal data we receive is feedback you voluntarily submit, most of your data is under your direct control on your own devices and Apple account. To exercise any rights regarding feedback data, contact us using the details below.
Security
We use Apple's platform protections for on-device and iCloud data, and industry-standard encryption in transit for any feedback sent to our backend. No method of transmission or storage is completely secure, but we take reasonable measures to protect your information.
Changes to this policy
We may update this Privacy Policy from time to time. We will revise the "Last updated" date above and, where appropriate, provide additional notice within the App.
Contact us
Joshua Boyd
[email protected]