HDZap Privacy Policy
Last updated: May 2026
Overview
HDZap is a lap-timer application. The free tier handles everything on your device and never contacts a server. The optional HDZap Premium subscription sends lap-announcement text to a cloud TTS service so the app can speak the call-out in a natural-sounding voice; that's the only path where data leaves your iPhone.
Free tier — no data leaves your device
With Premium disabled (the default), HDZap collects, transmits, or shares none of the following:
- Personal information (name, email address, phone number)
- Location data
- Usage analytics or crash reports
- Advertising identifiers or device identifiers
- Race history beyond your own iPhone
Race history (lap times, race records) lives in your iPhone's Application Support directory. It's included in standard iOS device backups if you have iCloud Backup or local backup enabled, but the developer never sees it.
HDZap Premium — what we send and to whom
When you enable HDZap Premium and select a Premium voice, the app sends each spoken phrase to our backend (operated by the developer on Cloudflare), which forwards the text to one of two text-to-speech (TTS) providers based on the voice you picked:
- AWS Polly (Amazon Web Services, Inc.) — for Polly Neural voices
- Azure AI Speech (Microsoft Corporation) — for Azure Neural voices
The provider synthesises audio and streams it back through our backend to your iPhone, which plays it through the speaker (or Bluetooth headphones, if connected).
What is sent
- The exact phrase the announcer reads: lap number, lap time, "best lap" cue, countdown numbers, etc. Example:
Lap 3, 12.34, best laporラップ3、12.34、ベストラップ. - The voice ID you selected, language tag, and (if applicable) rate / pitch adjustments.
- For subscribers: an Apple-signed JSON Web Signature (JWS) from StoreKit 2 confirming your subscription is active. The JWS contains your subscription product ID, expiration date, and original transaction ID; no Apple ID, email, name, or device identifier is included.
What is NOT sent
- Race history, lap data outside the current announcement, or any other accumulated data
- Your name, email, Apple ID, or any personally-identifiable information
- Location, IP geolocation, or device identifiers
How long it is kept
Our backend caches the synthesised audio (keyed on the same parameters above) for up to 30 days so repeated phrases ("Lap 5, 12.34", countdown "10", etc.) don't need to be re-generated. The cache holds audio only — never the request metadata. Cached entries are automatically evicted; nothing is retained indefinitely.
The TTS providers process each request to produce audio. Their data-handling policies apply:
- AWS Polly: aws.amazon.com/privacy
- Azure AI Speech: privacy.microsoft.com/privacystatement
Subscription billing
HDZap Premium is sold through the App Store. Apple handles all payment, billing, refunds, and identity. We never see your credit card information, Apple ID, or any other Apple-billed personal data — only the anonymous Apple-signed JWS token described above. To cancel: Settings → Apple ID → Subscriptions, or use the "Manage Subscription" button on the paywall.
Bluetooth
HDZap uses Bluetooth Low Energy (BLE) to talk to your M5StickS3 bridge device. The connection is direct device-to-device; no data passes through the developer or a third party.
Third-party SDKs
HDZap contains no third-party analytics, advertising, or data-collection SDKs. The Premium subscription path uses Apple's StoreKit 2 (built into iOS) and our own backend; no Firebase, Crashlytics, or similar.
Children
HDZap is not directed at children under 13. We don't knowingly collect data from anyone, so if a younger user installs HDZap, no data about them leaves the device.
Changes to this policy
We'll update this page if the data flow changes (e.g., a new TTS provider is added, the backend is moved). The "Last updated" date at the top is the canonical signal.
Contact
Questions about this policy: a@saqoo.sh