Privacy Friendly Ruler is a ruler and protractor application for Android, belonging to the Privacy Friendly Apps group developed by SECUSO Research Group at Technische Universität Darmstadt. This app is designed to display a ruler or protractor at the edge of the display, allowing users to take on-the-fly measurements with their smartphones. What sets Privacy Friendly Ruler apart from other similar apps is that it requires no permissions and contains no advertisements.

Privacy Friendly Ruler is a simple yet useful app that can be used by anyone who needs to take measurements. Its privacy-friendly design ensures that users can use it without worrying about their privacy being compromised. The app is available for free on the Google Play Store and can be downloaded easily. More information about the app can be found on the SECUSO Research Group website.