Facebook SDKs enable you to pass app event data from your app to Facebook. With app event data, you can accurately track and measure the actions people take in your app.
PHP: Hypertext Preprocessor is a server-side scripting language designed for Web development, but also used as a general-purpose programming language. PHP code may be embedded into HTML code, or it can be used in combination with various web template systems, web content management systems, and web frameworks.