5X5 – WordPress
A good collection of Chrome WP extensions, covering a wide range of applications.
If you are messing around with WP hooks you need to check out this reference:
DO NOT mess with WP-Theme files directly. If you do, you face disaster as you carefully crafted project will go up in smoke with the first Parent Theme update. If you use a child theme, your code variations on the parent theme will survive.
You may get whiplash looking at them all. This is a good place to start.
A good summary on how to do this directly in WP.