A free app for Android, by hellow network.
Wi-Fi Tools – Network Connection provides users with a free tool that can be used to analyze the connection quality of their WiFi networks. It will scan for the strongest signal in the area and identify which channels are congested.
What makes this tool special is that it can also detect any other devices connected to the same network and show the results in a simple and intuitive way.
In addition, it is very easy to use. In fact, there is no complicated procedure that has to be followed. You only have to select the WiFi you want to analyze.