There are many tools around to check your code and help you improve it: dialyzer, xref, erl_tidy, tidier, elvis. But running them all by hand is a tedious and, sometimes, cumbersome process. Gadget will automate all that for you, as long as you have your code hosted on a public github repository. He'll interject your PRs, check your code with all the tools you want and write comments on the lines you need to review.