Privacy Policy for SubnetCalc: IPv4 & IPv6

1. Introduction

SubnetCalc: IPv4 & IPv6 ("the App"), developed by AntoTech, is a professional utility and educational tool designed for network engineers, systems administrators, and students preparing for technical certifications (CCNA, CCNP, Network+). This Privacy Policy outlines our commitment to your data security. The App is engineered with a "Local-First" architecture, ensuring that your sensitive network configurations remain private and never leave your device.

By using the App, you agree to the collection and use of information in accordance with this policy.

2. Information Handling and Local Processing

The core philosophy of the App is Local-First Processing.

Calculation Data

Any IP addresses (IPv4/IPv6), CIDR masks, MAC addresses, or host requirements (VLSM) you input are processed in real-time using local JavaScript algorithms. This data is never transmitted to our servers or stored externally.

Persistence (Local Storage)

To improve your user experience, the App saves the following directly on your device using localStorage: your last calculated IP and CIDR mask, selected language, theme preference (Dark/Light), IP Detection Mode preference (Private/Public), Practice Mode XP/Score, saved Favorite subnets, and your Pro purchase status. This data remains on your device until you clear the App's cache or uninstall it, and is never synced to any account or server we operate.

3. Hardware and System Permissions

To provide a high-quality technical experience, the App utilizes the following system features:

Haptic Feedback (Vibration API)

The App uses the device's vibration motor to provide physical feedback during bit interaction and practice mode answers.

Clipboard & Social Sharing

Access to the clipboard and system sharing dialog is only triggered when you explicitly click "Copy," "Copy CLI," "Export Table (CSV)," or "Export PDF." This allows you to export data or configuration commands to other professional tools.

Network Interface Access

The App utilizes system APIs to retrieve your device's Local Private IP address (LAN). This is a read-only operation performed locally on the device to assist in network configuration tasks. No data about other devices on your local network is collected, scanned, or transmitted.

Network Access

Required for the third-party services described in Sections 4 and 5 below (IP detection, optional lookup tools, advertising, and purchases). The App does not browse your local network, scan connected devices, or access personal files.

4. IP Detection Services

The App offers two distinct modes for IP detection to assist in troubleshooting:

Private IP Detection (LAN)

This mode uses a native interface plugin to read the IP address assigned to your device's internal network adapter. This process is strictly offline and local.

Public IP Detection (WAN)

If you explicitly select "Public" mode, a secure HTTPS request is made to api.ipify.org (or similar services) to retrieve your exit IP address. This information is displayed directly to you and is not logged or stored by AntoTech.

5. Optional Network Lookup Tools

The App includes additional lookup tools that you activate voluntarily by entering a domain or IP address and tapping "Resolve" or "Query." These requests are sent directly from your device to the third-party service over HTTPS; AntoTech does not log, store, or have access to your queries.

DNS Lookup (free)

Resolves a domain name to its IP address using Google's public DNS-over-HTTPS service (dns.google).

IP Geolocation (Pro)

Retrieves approximate country, region, city, and internet service provider information for a given IP address using ipwho.is.

WHOIS Lookup (Pro)

Retrieves domain registration information (registration date, expiration date, nameservers) using the public RDAP protocol (rdap.org).

These tools only run when you actively use them; the App does not perform any lookups automatically or in the background.

6. Third-Party Services

Advertising (Google AdMob)

We use Google AdMob to display "App Open" advertisements when you launch or return to the App. AdMob may collect data including your approximate IP-based location, device/advertising identifiers, app interaction data, and diagnostic information to serve and measure ads, and to prevent fraud, as described in Google's data disclosure for the Mobile Ads SDK. We do not have access to the personal data collected by Google. For users in the European Economic Area and UK, the App displays a consent form (via Google's User Messaging Platform) before requesting ads, in compliance with GDPR. Advertising is fully disabled for users who purchase SubnetCalc Pro.

In-App Purchases (Google Play Billing)

The optional "SubnetCalc Pro" one-time purchase is processed entirely by Google Play Billing. AntoTech never receives, sees, or stores your payment card details; we only receive confirmation that a purchase was completed, which is used to unlock Pro features on your device.

App Updates (GitHub Gist)

On launch, the App checks a public, static text file hosted on GitHub to see if a newer version is available. This request does not include any personal or device-identifying information beyond a standard network request.

7. Data Security

No Cloud Sync

There is no user account system, cloud synchronization, or remote database. Your progress, favorites, and technical calculations are as secure as your physical device.

Technical Export

Exported CSV and PDF files are generated in-memory and passed directly to your device's native sharing system. We do not maintain copies of your exported network topologies.

Purchases

As noted in Section 6, payment processing is handled entirely by Google Play. AntoTech has no access to and does not store any financial information.

8. Children's Privacy

The App is a technical tool intended for students and professionals. We do not knowingly collect personal information from children under the age of 13. Since the App requires no login, we do not maintain a database of user ages or identities.

9. Your Rights and Choices

Data Deletion

You can delete all locally stored data (XP, settings, last IP, favorites, detection preferences, Pro status cache) at any time by clearing the App's storage/cache in your device settings.

Ad Preferences

You can opt-out of personalized advertising by adjusting the "Ads" settings on your Android or iOS device, or remove ads entirely by purchasing SubnetCalc Pro.

Restoring Purchases

If you reinstall the App or switch devices, you can restore your SubnetCalc Pro purchase at any time via the "Restore Purchase" option, which verifies your entitlement directly against your Google Play account — no personal data is required.

10. Changes to This Policy

We may update this Privacy Policy to reflect new features or changes in legal requirements. Any updates will be accessible within the App's sidebar menu.

11. Contact Us

For any questions regarding this Privacy Policy or the technical operation of the App, please contact us:

Email: tech.anto19@gmail.com