A self hosted geoip lookup application which provides a client with information about their IP address or any other. It uses the Maxmind GeoLite2-City database.
The webapp provides general geoip information. There is also an API.
Just what it says on the tin - it's a free service with an API that does GeoIP lookups for you. 15k queries/hour before you get cut off. Returns results as JSON, CSV, or XML in addition to returning the external IP of whatever host you're using.