Facebook Messenger

Facebook Messenger is an American messaging app and platform developed by Meta, Inc. 
It was originally developed as Facebook Chat in 2008. The company revamped its messaging service in 2010. It released standalone iOS and Android apps in August 2011 and standalone Facebook Portal hardware for Messenger-based calling in the fourth quarter of 2018. Later on, Facebook launched a dedicated website interface (Messenger.com), and separated the messaging functionality from the main Facebook app. This allows users to use the web interface or download one of the standalone apps.
In April 2020, Facebook officially released Messenger for Desktop. It is supported on Windows 10 and macOS and distributed on Microsoft Store and App Store respectively.