https://docs.omniref.com/ruby/2.2.3/
example annotation: https://docs.omniref.com/ruby/2.2.3/symbols/Class?#annotatio...
The "new" Omniref does a lot of things correctly that the "old" Omniref wouldn't (like working with programming languages other than Ruby...heh.)
If you have any trouble just send me an email: tim@omniref.com
I don't have any public examples of code review, but I've imported some popular open-source repos as examples (I don't know if I have these live-updating atm, so they might be a little behind their respective repos, but they're still good examples).
Here's the source for GitHub's libgit2 gem:
https://www.omniref.com/repositories/libgit2/rugged
And here's the source for reddit:
https://www.omniref.com/repositories/reddit/reddit
I'll work on getting some more of those on the homepage!