Signal Walk Privacy Policy

Overview

Signal Walk is a local-first Android field instrument. When you start a Walk Capture, the app reads supported wireless, motion, environmental, cellular, and location-quality signals from your phone so it can organize them into a timed session.

Signal Walk does not automatically upload your session content. Saved sessions remain on your device unless you explicitly export or share a file. Optional map and AI-related features can make third-party network requests, which are explained in this policy.

Information received by the developer

The Signal Walk developer does not operate an account system, session-data backend, or cloud session-storage service.

The developer does not receive or store your Signal Walk sessions or sensor observations. The bundled Google ML Kit SDK may separately collect limited device and app information, identifiers, feature events, performance measurements, and errors for Google's diagnostics and usage measurement. Those requests are described under Third-party network requests.

What the app reads and what a saved session stores

During a live Walk Capture, Signal Walk may read the following information, depending on your device, Android version, settings, and permissions:

• Counts and signal strength of nearby Bluetooth advertisements, not Bluetooth message contents
• Counts and signal strength of nearby Wi-Fi broadcasts, not network traffic or content
• Cellular network type and signal strength, not call content or contacts
• Motion readings from sensors such as the accelerometer and gyroscope
• Environmental readings from available pressure, light, proximity, and magnetic-field sensors
• Location-quality indicators such as fix availability and accuracy
• Battery and device-capability status used to describe the current session

When you finish and save a session, the app writes session metadata, event records, and any generated insight text into its private app storage. That saved-session data includes items such as the session name and timestamps, device and Android version, selected privacy and location modes, sample and event counts, recorded event titles and details, and saved insight summaries.

The current saved-session files do not persist raw Bluetooth MAC addresses, Wi-Fi SSIDs or BSSIDs, precise latitude/longitude coordinates, or full cell-tower identifiers.

Precise location and identifiers

Signal Walk is designed to exclude the highest-risk identifiers from saved sessions and report exports:

• Raw Bluetooth addresses are not written into saved-session files. Some explicit live snapshot views and exports may show only a masked form such as ••:••:XX.
• Raw Wi-Fi BSSIDs are not written into saved-session files. Some explicit live snapshot views and exports may show only a masked form such as ••:••:XX.
• If you turn on precise location for the live map, coordinates may be held in memory during the active session so the map can draw your path and event markers. The current saved-session files and report exports still omit precise latitude and longitude.

Privacy modes affect the content of saved-session report exports. They do not change the core saved-session metadata that the app keeps locally.

Exports and privacy modes

Signal Walk writes files only after you request them. The app currently supports multiple explicit export paths:

• Saved-session reports: Detailed, Redacted, and Summary-only modes control what is included in the exported report.
• Live snapshot export: a text snapshot of the current live view can include the current SSID, masked BLE identifiers, masked Wi-Fi BSSIDs, radio counts, and sensor readings that are visible at export time.
• Recorder export: a JSON Lines recording export can include per-sample counts, sensor values, and location-quality metrics, but not precise latitude/longitude or raw BLE or Wi-Fi identifiers.

The saved-session report privacy modes work as follows:

• Detailed: session metadata, event labels, insight text, and more telemetry for technical inspection, while precise latitude/longitude, raw BLE MAC addresses, raw Wi-Fi BSSIDs, and full cell identifiers remain excluded by design.
• Redacted: session metadata, event counts and labels, and higher-level sensor-state labels, while network identifiers, raw sensor magnitudes, and precise coordinates are removed.
• Summary-only: minimal session metadata, counts, and top event labels, with no event detail, no raw sensor values, and no location data in the export.

Third-party network requests

Signal Walk does not send session content to a developer-operated server. However, optional map features and Google's ML Kit infrastructure can make network requests to third parties.

Map tiles: MapLibre and OpenFreeMap

Signal Walk uses MapLibre, an open-source mapping SDK. Online map imagery is off by default, and the map begins in a field-grid or offline mode. Map resources are requested only after you opt in through the in-app disclosure or choose to download an offline region. The default provider configured in the app is OpenFreeMap.

As with any web request, a tile provider can receive your device's IP address and the requested style, tile, or offline-region resources, which can reveal the approximate area being viewed or cached. The provider handles that information under its own privacy practices.

Signal Walk does not receive or store information from those map-network requests and does not send session recordings or sensor histories to the map provider. Map resources may be cached on your device for reuse.

To avoid map-network requests, keep online maps disabled and do not download an offline region.

On-device AI: Google ML Kit, AICore, and Gemini Nano

Signal Walk uses Google's ML Kit GenAI client to provide optional on-device AI summaries on supported devices. AI summaries are user-initiated. The first time you choose Generate insights and accept the in-app disclosure, Google's infrastructure may download a compatible Gemini Nano model to your device. That delivery is governed by Google's Privacy Policy.

Signal Walk is designed to perform AI inference on-device without a cloud-inference fallback. The app builds the AI prompt from a sanitized session summary that excludes raw SSIDs, BSSIDs, Bluetooth addresses, precise GPS coordinates, private file paths, account data, and similar direct identifiers.

Google ML Kit may still contact Google for model delivery, compatibility checks, diagnostics, and usage measurement. The SDK may collect device and application information, installation or similar identifiers, SDK and model configuration, feature events, performance and reliability measurements, input/output size metadata, error codes, and configured language. This is Google SDK behavior, not developer-added advertising or behavioral analytics.

Signal Walk cannot delete information retained by Google. You can decline or disable AI summaries without affecting normal session capture, exports, or maps.

AI summary availability varies by device because it depends on compatible Google-provided on-device AI support and a successful model-availability check.

Information Signal Walk does not collect

• Your name, email address, or account information
• Raw Bluetooth MAC addresses or raw Wi-Fi BSSID values in saved-session files or report exports
• Precise GPS latitude and longitude in saved-session files or report exports
• The content of Bluetooth devices, Wi-Fi networks, or network traffic
• Call records, contacts, messages, photos, videos, or audio
• Background location, microphone data, or camera data
• Data from other apps on your device
• The Android Advertising ID

Signal Walk does not include an advertising SDK, does not sell personal information, and does not add a developer-operated behavioral analytics or crash-reporting service. Google ML Kit's separately disclosed diagnostics and usage measurement still apply.

Signal Walk does not pair with, join, advertise as, spoof, jam, or intercept nearby Bluetooth devices or Wi-Fi networks.

How local session data is used

Your on-device session data is used to:

1. Display live readings and saved-session results in the app
2. Create reports, snapshots, and recorder exports that you explicitly request
3. Generate supported on-device AI insights that you initiate

Signal Walk does not use your session content to train AI models, target advertising, or improve a developer-operated external service.

Exports and sharing

Signal Walk creates a file only after you request one. Android's sharing interface is opened only after you choose to export or share. The developer cannot see what you export, where you save it, or who receives it.

Once an export leaves the app, it remains under the storage, sharing, retention, and deletion controls of the destination you selected. Delete exported files separately when you no longer need them.

Storage, backup, and deletion

Session data is stored in the app's private directory at context.filesDir/sessions/. It is not normally accessible to other apps, is removed when you uninstall Signal Walk, and can be deleted from within the app.

Delete data from the app

• Delete one session: Sessions → open the session → overflow menu (⋮) → Delete session… → confirm
• Delete all sessions: Sessions → overflow menu (⋮) → Delete all sessions… → confirm
• Delete a downloaded offline map region: Live map card → overflow menu (⋮) → Delete offline region → Delete cached region

Files already exported outside Signal Walk must be deleted from the location where you saved or shared them.

Children's privacy

Signal Walk is not directed to children under 13, and the developer does not knowingly collect personal information from children.

Changes to this policy

If this policy changes, the date at the top of the page will be updated. Significant changes may also be noted in Google Play release information.

Contact

For privacy questions or requests, email privacy@signalwalk.com.

For a product-support question that is not about privacy, email support@signalwalk.com. To report a potential vulnerability, email security@signalwalk.com.