Privacy Policy

Short version

Pink Trail lets you pick a short video from your own Photos library and uses Apple's Vision framework (VNDetectTrajectoriesRequest) to extract the parabolic flight path of a moving object — a ball, a bird, a thrown stone. The resulting trajectory polyline, parabola equation, and a single middle-frame thumbnail are saved on your device. There are no accounts, no analytics, and no third-party SDKs that contact a server. The only network calls the app makes are to Apple's StoreKit when you choose to subscribe or unlock the Lifetime tier.

Who we are

Pink Trail is published by Danielius Studio LLC, a Wyoming limited liability company at 30 N Gould St, Suite #5280, Sheridan, WY 82801, USA (“we”, “us”).

Data we do NOT collect

• No account, no email, no password — the app has no signup.
• No analytics, no telemetry, no event tracking.
• No advertising identifiers (no IDFA, no fingerprinting).
• No usage data sent off the device.
• No camera, no microphone. Pink Trail never opens the camera or records audio; it only reads short videos you explicitly pick.
• No location, no contacts, no calendar.
• No HealthKit, no Health data.

Photos permission

Pink Trail requests Photos access (the NSPhotoLibraryUsageDescription permission) so that the system picker can show you videos to choose from. The permission is used only to read the short video you explicitly pick through Apple's PhotosPicker.

Pink Trail does NOT scan your broader library, does NOT build an index of your photos or videos, does NOT extract face data, EXIF, or location metadata beyond what is intrinsic to the frames it reads, and does NOT use any Vision request other than VNDetectTrajectoriesRequest for parabolic-trajectory detection.

On-device trajectory detection (Vision framework)

When you pick a short video, Pink Trail samples its frames and runs Apple's VNDetectTrajectoriesRequest on-device. The request returns parabolic motion paths it identifies in the footage. The app fits the dominant path to a quadratic equation (y = ax² + bx + c) and stores the resulting points and coefficients alongside a single middle-frame thumbnail.

All Vision processing runs on your iPhone's Neural Engine and CPU. The video bytes and every intermediate frame stay in memory on your device and are never uploaded.

What stays on your device

• Your trail entries: a 512px middle-frame thumbnail (PNG), the trajectory point list (an ordered array of (x, y) coordinates), the parabola equation coefficients (a, b, c), and the created-at timestamp. Stored in on-device SwiftData with the thumbnail held as external storage.
• Optionally, a copy of the source video clip you picked, if you choose “Save source clip” on the entry screen. Stored in on-device SwiftData as external storage. You can delete the clip at any time and keep just the trajectory.
• The date the app was first launched (used to time the free window and gate the Pro upsell). Stored in UserDefaults.
• Whether the intro flow has been acknowledged.

The original video continues to live in your Photos library. Pink Trail keeps only the trajectory data, the equation, the thumbnail, and (optionally) a separate copy of the clip. Pink Trail never modifies, deletes, or writes back to the original.

All of the above lives on your device and never leaves it. Uninstalling the app deletes everything Pink Trail has stored.

In-app purchases

If you choose to subscribe (Monthly, Annual) or buy the Lifetime unlock, that transaction is handled by Apple's StoreKit. Apple processes the payment and shares only the receipt with the app so we can verify your entitlement. We never see your card number, billing address, or any personal information beyond Apple's opaque transaction identifier.

Subscription receipts are stored on-device by iOS and used to validate your entitlement when you re-open the app. They are not sent to any server we operate.

Family Sharing

Pink Trail Pro purchases (Monthly, Annual, Lifetime) are Family-Shareable through Apple's standard Family Sharing mechanism. Apple handles eligibility checks; we do not see who is in your family group.

Children

Pink Trail is rated 4+ in the App Store. Because the app collects no data at all, it complies with COPPA and similar children's-privacy regulations by design.

Your rights

Because Pink Trail does not collect data, there is nothing for us to export, correct, or delete on your behalf. To revoke Photos permission, use iOS Settings → Privacy & Security → Photos. To remove all on-device state, delete the app.

For questions, write to dchalikovasss@gmail.com.

Changes

If we ever introduce a feature that involves any data leaving the device (for example, cloud sync or sharing), this page will be updated and the “Last updated” date at the top will change. For v1.0, no such feature exists.