OpenWifiStatistics is an Android application used to scan wifi networks, gather statistics about them like BSSID, signal level, frequency, security settings and location and upload the data to a server for analysis. It is open source and you can view the code for the android app here <a href="https://www.google.com/url?q=https://www.google.com/url?q%3Dhttps://github.com/uberspot/OpenWifiStatistics%26sa%3DD%26usg%3DAFQjCNEZK0jRTuFgmiBtz5zu45zk4yjjJA&sa=D&usg=AFQjCNEQwftIpKlO41lMOJ8_kk2M9qWDJw" target="_blank">https://github.com/uberspot/OpenWifiStatistics</a> and the code for the web interface here <a href="https://www.google.com/url?q=https://www.google.com/url?q%3Dhttps://github.com/uberspot/OpenWifiStatistics-web%26sa%3DD%26usg%3DAFQjCNF6EK1MlM-pT_0qIBUkAWVcWvGDbg&sa=D&usg=AFQjCNHtGAhfg2OOefLbP4r8Kkzkao8GUw" target="_blank">https://github.com/uberspot/OpenWifiStatistics-web</a>
This projects isn't actively developed for a long time now.
Note: No personal data (name, device info etc) are transmitted. There is no correlation between the wifi statistics and the devices that recorded them.