WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
ipstack - ipstack is a free, real-time IP address to location JSON API and database service supporting IPv4 and IPv6 lookup.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
ipapi - Web analytics with IP address lookup and location API
Zulip - Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.
ipgeolocation.io - Free IP Geolocation API and Accurate GeoIP Lookup Location Database