As part of my job I often perform application reviews and code quality analysis for clients who wish to have their code base looked at by an independent company. Running static analysis tools is usually a starting point to the review as it gives a general overview of a state of the project. I also like to run those tools as part of an introduction to an inherited code base.
For an easy access to the most popular static analysis tools for PHP I recently created a docker image - phpqa.
He lists out the tools that are included with the current version (a quite lengthy list) including:
...and many more. Check out the full post for more of the tools in the list and links to more information about each one.