Long time ago I wrote small program to filter EXPLAIN ANALYZE output, and add summary of time.
A bit later (I guess, I don't recall exact time line, it could have been earlier) Michael Glaesemann started explain-analyze.info – cool tool for checking what might be wrong with given plan.
I'm not really happy with the emphasis Michael put on bad rowcount estimates, so I decided to write my own tool. Enter explain.depesz.com.
Basic idea is: paste your explain analyze plan, and see the output. You can click on column headers to let it know which parameter is the most important for you – exclusive node time, inclusive node time, or rowcount mis-estimate.
It is definitely not perfect. I know of at least 1 bug now, and will fix it in not-distant future.
But, as for now – you can test it, play it, or simply use it. If you'd like to change/fix something – sources are freely available. Just be warned – it's Perl ;-P