In research and academic contexts, "plug-in Facebook" usually refers to one of three distinct areas: the (audio research), Social Plug-ins (privacy/data law), or Browser Plug-ins (behavioral science).
Facebook plugins, also known as social plugins, are tools that allow website owners to integrate Facebook features into their websites. These plugins enable users to interact with Facebook without leaving the website. Some popular Facebook plugins include: plug+in+facebook
This allowed power users to chat with Facebook friends alongside AIM, MSN, and Yahoo contacts. Unfortunately, Facebook killed XMPP access in 2015, making these plugins obsolete. Facebook Spatial Workstation 360º In research and academic
These are ready-made code snippets provided by Facebook for developers: Solution: Delete the old plugin