I've been using this tool for a while for my own work (I'm generally using Vim, not any IDE) and thought that it might be useful for others.
It's the Nim equivalent of ctags; i.e. a tool to generate a tags file from source code in order to quickly look up declarations in editors that support them. The parser still is fairly primitive in that it only handles top-level declarations, but that should still handle the majority of use cases (other than enum members).
The source is available here. I may submit a PR to include it in the Nimble package list later (so that it can then simply be installed with nimble install ntags).
Yes, it still exists, at https://bitbucket.org/nimcontrib/ntags.
It is maintained insofar as I haven't found any need to update it, other than check on and off to make sure that it works with the most current version of Nim. The main features that are missing are support for enums and object fields, but for that I'd have to likely write a more featureful parser than the current ad-hoc solution.
I do not use tagbar, so I have never looked into that.