Now there's another way to reuse your old smartphone: turning it into a surveillance system to detect any intruder trying to breach your privacy and security.
To achieve this you need the open source Android app called Haven, which was created by Edward Snowden.
When installed on an Android phone, the Haven app activates various sensors on the device. It uses the front and rear camera sensors to look for any changes in motion in the environment. It also uses the microphone to detect changes in sound level.
The app uses the ambient light sensor to detect changes in ambient light. The accelerometer is used to detect changes in the device's own motion. The app also monitors whether the device is charging or losing power.
You can easily keep an eye on everything going on around your Haven-powered device as it regularly sends recorded messages and other information to your primary smartphone via Signal. You can also access Haven's log over the internet using Tor or if you have physical access to the device.
Where can Haven be used? Well, there are many places. You can place a Haven-powered device next to your valuables to record any suspicious activity and prevent any unwanted thefts. For example, it could be your laptop that contains some confidential documents.
However, there are some issues that may hinder the effective functioning of the monitoring system. Haven will require an internet connection. So, a user will have to make sure that the device uses data in case WiFi connection is not available. Disabling real-time alerts or receiving them via SMS could be a solution.
A person who knows the device's password or PIN could potentially delete the app's log if they have physical access to the device. Another concern is that the attacker could disable the device's sensors, putting it at risk remotely.
The open-source Android app is currently in public beta and can be downloaded from Google Play and F-Droid.
