A little Java Script app written using Vanilla Java Script that is using MapBox API to show the map, Geonames.org API to geocode locations and IP Info DB API to identify IP address.
Requires nothing except opening HTML in browser. All job is done on client-side (i.e. in browser) and can be run locally without the need for any server.
However, it cannot be hosted as is on any custom domain due to CORS policies limitations executed by Browsers.
I've done a separate implementation to support deployment for custom domains and using server API.