The oracle open source Logger instrumentation library is gaining popularity and it would be great to build some specific support for it into SQL Developer, whether as a plugin or builtin.
https://github.com/OraOpenSource/Logger
I have some suggestions for making SQL Developer work better for developers using Logger:
1. Add an option or toggle to hide/show or dim (i.e. grey highlight) all lines with calls to logger, e.g.:

Perhaps it could be an option that takes the name of the package as a parameter, e.g. "logger" so that it might be useful for other use cases.
2. Add a code generator, that given a function, procedure, or package body (with many functions/procedures), will add all the standard bits to instrument it with Logger - as per the Best Practices document: https://github.com/OraOpenSource/Logger/blob/master/docs/Best%20Practices.md
Thanks, open to discussion on these ideas.