A free app for Android, by Webprovider.

In the 21st century, people spend more time connecting to the Internet than in previous decades. For many of us, connecting to the Internet is a crucial part of daily life, and the way we connect is changing. As mobile phones have become an integral part of our everyday lives, we have started to rely on mobile networks for our Internet connection. However, connecting to the Internet through a mobile network can be a frustrating experience, due to poor signal quality and the frequent delays caused by the network.

To make the Internet more usable on your mobile phone, you can use the Wifi Heat Map app. With this app, you can create a heat map of the Wi-Fi signal quality in your flat, house, apartment, or shop. You can draw your flat on paper or use existing plans and take a picture with a device camera. After that, just walk into desired space and click on the display on your exact location. The signal quality of your Wi-Fi will be placed on that map.

Because of this, all apps will eventually require the location permission as noted here: “To access the hardware identifiers of nearby external devices via Bluetooth and Wi-Fi scans, your app must now have the ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION permissions.