Core commitment. Photo decoding, alignment, stacking, editing, and Core ML inference happen on your device. Celvion Stack does not operate a photo-processing server.
1. Scope
This policy applies to the Celvion Stack app for iOS and iPadOS and to this official website. Celvion Stack is an on-device tool for photo stacking, RAW image processing, color adjustment, denoising, and super-resolution enhancement.
2. Information the App Accesses and Why
Celvion Stack accesses information only as needed to provide features you choose to use.
- Photos and files you select: image pixels, file names, dimensions, color information, and capture metadata included with the file may be used to import, align, stack, edit, enhance, preview, and export your images. The app does not browse other content without your selection or permission.
- Photo Library add permission: used only when you choose to save a processed result to Apple Photos.
- App preferences and recovery state: language, export options, performance preferences, and a brief interrupted-task state are stored on your device to remember your choices and improve reliability.
- Device operating conditions: available memory, processor capability, Low Power Mode, thermal state, and available disk space are used only on device to tune performance, reduce heat or memory risk, and warn before large exports.
- Local operational logs: the app may keep startup times and processing-stage information that does not contain photo content inside its sandbox to help diagnose startup or interrupted-processing issues. This information is not sent to the developer automatically.
3. On-Device Processing, iCloud, and File Providers
Photo decoding, alignment, stacking, editing, and Core ML model inference take place on your device. Celvion Stack does not upload photos, RAW files, or processed results to servers operated by the developer.
If an item you select is not stored locally, Apple Photos, iCloud Drive, or a file provider you choose may download it at your request. That transfer is handled by the relevant system or provider under its own privacy policy; it is not a transfer from Celvion Stack to the developer.
4. Collection, Tracking, and Sharing
Celvion Stack currently requires no account and includes no advertising, cross-app tracking, third-party analytics SDK, or developer-operated remote diagnostics service. The developer does not collect, sell, or share your photos, profile information, device identifiers, or app usage history.
When you use the system share sheet or export features to send a result to another app, cloud drive, website, or person, you initiate that transfer. The destination handles the content under its own terms and privacy practices.
5. Storage and Retention
- Original photos and files remain at the source you selected. Celvion Stack does not modify the originals.
- Temporary files and local caches may be created during processing. They are removed when a task finishes, during cleanup on a later launch, or when the operating system reclaims storage.
- Language, export preferences, performance settings, local recovery state, and startup logs may remain in the app sandbox until updated, cleared after recovery, or removed when you uninstall the app.
- Exported results remain in the Photos library or Files location you choose until you delete them.
- Where supported by the output format, an export may retain technical metadata from the source image, potentially including capture time, camera information, or location already present in the original file. Review or remove metadata before sharing when appropriate.
6. This Website
This website does not offer accounts, run advertising, use analytics, or set tracking cookies. The language selector uses only the page URL parameter and does not create a user profile.
The site is hosted by GitHub Pages. Like most hosting providers, GitHub may process connection information such as IP addresses and request logs to deliver and secure the service. That processing is controlled by GitHub under its privacy statement.
If you email support, your email provider and the receiving email service process the message you choose to send. The developer uses it to respond to your request and retains it only as reasonably needed for support, legal, or security purposes.
7. Your Choices and Controls
- You choose which photos or files to process and can change Photos access in iOS Settings.
- You can cancel an import or processing task and delete exported results yourself.
- Because the developer operates no app account system or remote app database, there is no server-side app profile for the developer to retrieve or delete. Uninstalling the app removes its local settings, caches, recovery state, and logs. Results saved to Photos or Files must be deleted separately by you.
- You may contact the developer about a support email you previously sent and request deletion when applicable.
8. Children’s Privacy
Celvion Stack is not designed to collect personal information from children and does not ask any user to create an account or submit profile information. Children should use photo processing and sharing features with guidance from a parent or guardian.
9. Security
The app relies on the iOS sandbox, system permissions, and device security features to isolate local data. No storage or software system can guarantee absolute security, so protect your device, keep backups of important originals, and review content and metadata before sharing.
10. Changes to This Policy
If the app’s features, the website, or data practices change, this policy and its effective date will be updated. If a change materially affects your rights in the app, an appropriate notice will be provided in the app.
11. Contact
Developer: Xinyu Guo
Email: guogxy@hotmail.com