request-ip
A small Node.js module to retrieve the request's IP address
proxifly
Proxifly is a service to get free HTTPS proxies and check your public IP
req-real-ip
This library allows you to get the real ip address of a user. It gives you the real ip address even if the request header is modified.
advanced-proxy-checker
NPM module to check proxy speed, fraud-score, latency and every other information of proxies.