I am currently trying out https://www.codacy.com
on my fork of the radiology module https://www.codacy.com/app/mrteleivo/openmrs-module-radiology/dashboard
and I like it showed me some issues where we would run into null pointer exceptions
Its free for open source projects. I would like to make code quality visible for others, since now will get a lot more different contributors on the radiology module. coveralls for code coverage, has proven to be a great quality gate already. some more focus on quality would be a fantastic addition!