by Beebo
Version 1 (January 26, 2025)
Download (14 downloads)
An attempt at a flow recognizing phone placement in a Faraday environment, and subsequently triggering an audible alarm.
This flow should be considered a proof of concept rather than a security solution. If a thief were to steal your phone and place it in a Faraday bag instead of turning it off, they would likely only be startled by the alarm.
There is a high likelihood of false positives in remote or secluded areas with few devices nearby, such as tunnels.
How it works:
- Detect cellular signal loss, which prompts scanning of surrounding cell towers, Bluetooth, and Wi-Fi devices.
- Sound an alarm if all device scans return no results.
Limitations:
- Requires Wi-Fi, bluetooth, and cellular to be enabled in order to reduce the risk of false positives.
- Wi-Fi scans are limited to once every 30 minutes. If another app has recently performed a scan, the flow will cancel its execution. It is possible to disable this limit in the developer settings, but doing so has privacy risks.
- The "cell tower near" block works on some devices only when the screen is on, so may need to check and adapt the flow if that's the case.
- While it would be preferable to use the "cell tower near" block set to "when changed," this doesn't work due to a quirk in my device's Android version.
Setup:
Ensure you change the alarm sound to one available on your device and choose a valid notification channel, allowing for easy alarm cancellation.