Privacy Policy

NetTopology — Last updated: April 28, 2026

NetTopology ("the App") is a network diagnostic and topology visualization tool for iOS. This Privacy Policy explains how data is handled when you use the App.

Data We Do Not Collect

NetTopology does not collect, store, transmit to our servers, or share any personally identifiable information. Specifically:

• We have no backend server.
• We do not use third-party analytics SDKs (Firebase, Google Analytics, Sentry, or similar).
• We do not require you to create an account.
• We do not track you across other apps or websites.
• We do not share data with advertisers.

Data Processed Locally on Your Device

The following operations are performed entirely on your device or within your local network. This data does not leave your device or LAN:

• Network scanning: Ping, Traceroute, mDNS/Bonjour service discovery, TCP port probing.
• Device fingerprinting based on advertised services and HTTP banners on your local network.
• Wi-Fi gateway and DNS resolver detection.
• Discovered device names, IPs, and service metadata are kept only in memory while the App is running.

Third-Party Service: ipwho.is

To display your external IP address, ISP, and approximate geographic location on the dashboard, the App makes a real-time HTTPS request to ipwho.is, a third-party IP geolocation service.

• Your public IP address is naturally exposed to ipwho.is as part of any HTTPS connection.
• The response is displayed to you immediately and is not stored by NetTopology.
• NetTopology has no control over ipwho.is's logging or retention practices. Refer to ipwho.is's privacy policy for details.

Permissions

• Local Network (NSLocalNetworkUsageDescription): required to discover devices and diagnose your network. Without this permission, mDNS discovery and LAN scanning will not function.

Children's Privacy

NetTopology is rated 4+ and does not knowingly collect personal information from anyone, including children under 13.

Changes to This Policy

This policy may be updated as the App evolves. Updates will be posted here with a revised "Last updated" date. Continued use of the App after changes constitutes acceptance of the updated policy.

Contact

Questions about this Privacy Policy can be sent to: gaoyingze1906@gmail.com