SignalKit - Privacy Policy

Last updated: April 18, 2026

Overview

SignalKit ("the App") is a real-time audio spectrum analyzer. It measures the audio captured by your device's microphone and displays it as a frequency spectrum, plus optional per-band calibration, measurement history, and branded PDF reports. Your privacy is important to us. This policy explains what data the App accesses and how it is used.

Data Collection

SignalKit does not collect, transmit, or share any personal data with the developer or any third party.

• No analytics - We do not use any analytics or tracking services.
• No accounts - No sign-up or login is required.
• No cloud storage - All data stays on your device.

Microphone Access

SignalKit requires microphone access to measure audio levels and display a frequency spectrum. Audio is processed locally on your device and is never transmitted, stored, or uploaded. The microphone is only active when you explicitly start a measurement.

USB Audio Devices

SignalKit can optionally route audio capture from a connected USB microphone (e.g., a measurement microphone). The USB device list is read locally and is never transmitted. You must explicitly grant permission the first time each USB device is connected.

Camera and Screen Recording

SignalKit can optionally record video of a measurement session - either the screen (via Android's MediaProjection API) or rear-camera video. Both require explicit user consent at the time of recording. Resulting video files are saved to your device's app storage and never leave your device unless you explicitly share them.

Measurement Data

Calibration profiles, imported microphone correction files, saved measurements (including optional polarity / impulse-response / STI test results), project notes, video recordings, and generated PDF reports are stored locally in your device's app storage. They never leave your device unless you explicitly share them (e.g., exporting a PDF via your device's share sheet).

Advertising (Free Version)

The free version of SignalKit may display advertisements through Google AdMob. AdMob may collect device-identifier and usage information to serve relevant ads. See Google's Ads policy for details. The Pro version is advertisement-free.

In-App Purchases (Pro and STI Add-On)

SignalKit Pro and the optional STI (Speech Transmission Index) add-on are purchased through Google Play Billing. We do not receive your payment information. Purchase status is stored on your device and restored via your Google account if you reinstall the app.

Permissions

• RECORD_AUDIO - Required for spectrum measurement.
• MODIFY_AUDIO_SETTINGS - Used to configure the audio session for accurate measurements.
• CAMERA - Optional. Used only when you choose to record rear-camera video of a measurement.
• FOREGROUND_SERVICE / FOREGROUND_SERVICE_MEDIA_PROJECTION - Optional. Required by Android when you choose to record the screen during a measurement.
• USB Host - Optional. Used only when you explicitly select a USB microphone as the audio source.
• INTERNET - Used only for ad delivery (free version) and in-app purchase verification.

Children's Privacy

SignalKit is not directed at children under 13 and does not knowingly collect personal information from children.

Changes to This Policy

We may update this policy from time to time. The "Last updated" date at the top of this page will reflect any changes.

Contact

Questions or concerns? Email [email protected].