When working through a complex project in Jira the question I always ask is "what are the blockers, and what are the blocker's blockers." There are some plugins that answer this question, but maybe not in the way I want.
This project presents the blockers and their child blockers in a tree-like format. This doesn't really catch the possible complexity of a set of Jira issues, which are more of a graph. However, for my uses it's a quick way to get a handle on what needs to be done first.
In order to use it you'll need to generate a user token for yourself.
go run . -user=username@example.com -token=asdf1234 -issue=ISS-123
You may also pass a -depth flag if you'd like to shorten or lengthen the tree depth from the default 3.
Caveat emptor, there's very little error handling and the JQL query is fragile to say the least.