Facebook Messenger is an instant messaging service and software application. It is integrated with Facebook’s web-based chat feature. Facebook Messenger lets Facebook users send messages to each other. It was launched as a standalone app on the Android and iOS operating systems in August 2011 and the functionality was then removed from the main Facebook app in April 2014. Facebook has also launched Facebook Messenger Lite, a basic app with a limited feature set for areas with low-speed Internet or old mobile devices.