Privacy policy

Effective 21 October 2026.

Summary

NetWrench does not collect personal data, does not share data with third parties, and requires no account. The application contains no analytics, no crash reporting and no advertising libraries. Everything it measures stays on the device. The one thing that can reach the developer is a router report, and only when the user presses “send data” (see “Router report” below).

Data processed on the device

The application works with technical information about the network the phone is attached to. It is processed locally and does not leave the device unless the user exports a report:

• connection parameters: IP address, netmask, gateway, DNS servers, connection type;
• wireless networks in range: network name, BSSID, channel, signal level, security mode;
• devices found on the local network during a user-initiated scan: address, MAC address, hostname, vendor by OUI, state of individual ports;
• data obtained from the router over its management protocol: model, firmware version, interface list, MAC and IP addresses, WAN and Wi-Fi settings;
• mobile network information, while the Cellular tab is open: operator, MCC and MNC, network type, cell and area identifiers, signal level;
• measurement results: latency, loss, throughput, traceroute and diagnostic output.

This information may be included in a diagnostic report. Reports are produced locally and are shared only when the user explicitly chooses to share one.

Router credentials

Router usernames and passwords are entered by the user. They are stored on the device in the Android Keystore and are used only to reach that router over the local network. They are never sent to the developer and are never written to application logs or diagnostic reports.

Purchasing the full version

The application is free; the full version, which lifts the daily limits, is a one-time purchase through Google Play. Payment is taken and processed by Google under its own privacy policy — payment details are not passed to the application or the developer. The application tells the developer nothing about a purchase; the order details Google Play shows the seller are used only to handle refunds.

The purchase receipt is stored on the device and its Google signature is verified there. Whether the purchase is still valid the application asks Google Play on the phone — it has no verification server of its own. The free version's daily counters are likewise kept only on the device.

Permissions and why they are needed

Network connections

The application connects only to hosts determined by what the user is doing:

• the router and local network devices, during discovery, configuration reads and scanning;
• the throughput-test server the user selected or entered;
• public hosts used to check Internet reachability and measure latency;
• the ipwho.is service, to identify the Internet provider behind the connection’s public IP address. Such a request necessarily discloses that public IP address to the service, as any Internet request does; no device identifier and no application data are sent, and the response is not retained beyond the current session;
• raw.githubusercontent.com, for reference files: the router factory-login data and the router model catalogue (the zortald/netwrench-data repository, files router-defaults.json and router-catalog.json). The application checks them by itself at launch when the Internet is reachable, at most once an hour, and when the user presses “Check” in Settings; the request discloses the public IP address to GitHub, as any Internet request does, and carries no device identifier and nothing about the network the phone is on;
• script.google.com, for a router report, only after the user presses “send data” (see “Router report”);
• raw.githubusercontent.com, for the user-script catalogue (the same zortald/netwrench-data repository, file userscripts.json). It is fetched only when the user opens the catalogue in Settings; the file lists addresses and contains no code itself;
• the address a user-installed script is published at, when it is installed and when it is later checked for an update. The request goes to the host the script's author named, over https only;
• Google Play, through its services on the phone, to buy the full version and to check that the purchase is still valid;
• netwrench.app, for the release notes the application reads when Google Play reports an update as available;
• the address a page opened in the Web tab asked for — only when the user has separately enabled this for that one saved address. Enabled, it lets the page ask the application to reach the address it names using the phone's own network stack, and returns the response, reusing the built-in browser's shared cookie storage; this is how, for example, a site that blocks requests from server addresses is still reached. The exchange runs directly between the phone and the address the page named — the application does not store this data and does not send it to the developer.

There are no developer-operated servers receiving telemetry.

Router report

When the application cannot identify a router's model, or the model is missing from the model catalogue, the router card offers “send data”. Only then does the application send the developer a report, from which the model is added to the catalogue. A report is never sent on its own. It contains:

• the vendor, model and firmware version as the application identified them, the router's address on the local network, and its network name if the router reports one;
• the first three bytes of the router's MAC address — the vendor code; the full MAC address is not sent;
• the Wi-Fi bands, standard and security mode the phone hears; network names are not sent;
• what the router shows without a login: the responses of its web interface (headers and page content), which of a fixed list of service ports are open, the greetings of its FTP, SSH and Telnet services, its MikroTik Neighbor Discovery reply and its UPnP device description. The login page is sent as served and may carry what is configured on the router, such as its name;
• the application version and a random identifier created on the phone for this router, to tell a repeated send from a second router of the same model. It identifies neither the phone nor the router.

Passwords and other credentials, information about other devices on the local network, location and phone identifiers are not part of a report. As with any Internet request, the receiving service sees the public IP address the request came from.

The report goes to a Google Apps Script service and is stored in the developer's Google Sheets and Google Drive. Reports are used only to extend the model catalogue and are not shared with third parties. If there is no Internet when it is sent, the report is kept on the phone — at most ten, for at most 30 days — and sent by itself once the Internet is back.

User scripts

On the Web tab a user script can be installed — a small JavaScript program that runs inside an open page, the way an extension does in a desktop browser. The user installs it: by address, by pasting its text, or by choosing it from the published catalogue. Nothing installs itself, and nothing is installed by default.

A script runs only on the addresses listed in its own header, and inside such a page it sees that page's content and cookies — exactly as much as the page's own code does. Neither the text of a script nor the addresses it ran on is sent anywhere. Downloading a script and checking it for updates happen over https only.

A script is somebody else's code, and whoever wrote it is responsible for it. Every installed script is listed in Settings, where it can be opened and read, disabled or removed.

Children's data

The application is intended for professional use and collects no personal data, including data of children under 13.

Sharing with third parties

Data is not shared with third parties, not sold and not used for advertising. Router reports the user sent are stored in the developer's Google services (Sheets and Drive); Google processes them under its own privacy policy.

Data deletion

The application creates no account. A router report that was sent is deleted by the developer on request to the address below — give the router model and roughly when it was sent. Everything it stores — settings, report history, and router credentials in the Android Keystore — is kept on the device only, and is removed entirely when the application is uninstalled or its data is cleared in Android settings.

Who is responsible for the application

NetWrench is developed by an independent developer. Enquiries about data handling go to the address below.

Changes

Revised versions are published on this page with their effective date. Material changes will be noted in the application's store listing when it is updated.

Contact

Questions about how the application handles data: onufriev.serg@gmail.com