My standard debugging tool when using PHP is xdebug. Pairing xdebug with Komodo gives me a very productive environment for building PHP applications. However, testing an application code on a hosted server can be many times frustrating as one has only the print_r and var_dump functions at our disposal. What I need is a library that I can easily install on the server and start using. Although there are a few debugging libraries around, one of my favorites is Kint.
He walks you through the installation of the tool and provides an example of the most basic usage (and output) from a call to the tool's "dump" function. He also gets into some of the additional features the library provides including intelligent formatting, debug tracing and limited theme configuration.