CellID Finder - Find a cell phone location using LAC/CellID, GSM BTS coordinates
WiFi Map - A crowdsourced list of routers and passwords
OpenCellID - OpenCelliD is the largest Open Database of Cell Towers & their locations. You can geolocate IoT & Mobile devices without GPS, explore Mobile Operator coverage and more!
Café Wifi Search 🔍 - Find great cafés to work from, worldwide.
wigle.net - WiGLE (Wireless Geographic Logging Engine)
Instabridge - Crowdsourced free wifi (now on Android)