CIS Optical Calculator does not require an account and does not use analytics, cross-app tracking, or third-party advertising networks. Calculator inputs and saved history remain on the user's device.
Information stored on your device
The App stores the following information locally on your device:
- calculation history and optional labels you choose to save;
- your light, dark, or system appearance preference; and
- cached partner-content configuration and images.
Calculator values, saved history, and preferences are not transmitted to the developer, GalaxyCore, or linked third-party services. You can remove saved history from within the App. Other locally stored data is removed when the App is uninstalled, subject to the normal behavior of your device and backups.
Network requests and server logs
The App contacts config.etgel.xyz to retrieve a small partner-content configuration and related images. Native versions stage banner-image downloads while connected to Wi-Fi. These requests do not contain calculator inputs, saved history, names, email addresses, advertising identifiers, or account identifiers.
Like most web servers, our server records limited technical request information, which may include an IP address, request time, requested path, response status, and browser or device user-agent information. These logs are used only to deliver content, maintain reliability, and protect the service. Under the current server configuration, logs are rotated daily and retained for approximately 14 days. They are not used for advertising, profiling, or cross-app tracking.
External links
Clearly labeled partner-content banners may open official GalaxyCore or WeChat pages in the system browser. Third-party names, logos, product images, and linked articles belong to their respective rights holders. Once opened, those third-party services process information under their own privacy policies and terms. The App does not receive your browsing activity from those external pages.
Operator and content relationship
CIS Optical Calculator is independently developed, published, and operated by Etgel Lu. The App includes links to GalaxyCore product information. GalaxyCore is not the publisher or operator of the App and does not receive calculator inputs or saved history through the App.
Sharing and sale of information
We do not sell personal information. We do not share App data with data brokers, advertising networks, or analytics providers. Infrastructure providers may process limited technical information only as needed to host and secure the banner service.
Children's privacy
The App is a general engineering calculator and is not directed to children. We do not knowingly request or collect personal information from children through the App.
Changes to this policy
We may update this policy when the App or its data practices change. The effective date below will be updated when a revised policy is published.
Contact
For privacy questions, contact etgel_lu@hotmail.com.