ipstack - ipstack is a free, real-time IP address to location JSON API and database service supporting IPv4 and IPv6 lookup.
SafeGraph - SafeGraph's Points-of-Interest (POI) data, geofences, business listings, & foot-traffic data empowers firms to do better geolocation, marketing attribution, retail analytics, & location intelligence.
ipapi - Web analytics with IP address lookup and location API
ipgeolocation.io - Free IP Geolocation API and Accurate GeoIP Lookup Location Database
GeoNode.org - Open Source Geospatial Content Management System
ipinfo.io - Simple IP address information.