Embrace that 3rd Party Universe :) Comment with your best links. I will try to update this and maybe some day we can make this a sticky.
https://edtools.cc/ all around a very good site with good tools for bounty hunting, trading, mining
https://edmining.com/ complete infos about mining. Builds, places, tips
https://inara.cz/ you should know this! link it to your accoutn and enjoy one of the best sites about elite
https://edsy.org/ tinker with ship builds. you can choose, ships, modules, blueprints and see exact values and changes
EDMC-Massacres is a plugin for EDMC which helps you keep track of total kills required when stacking pirate massacre missions.
If you don’t know about Massacre Stacking, here’s an explainer (youtube), (piped mirror).
Also… full disclosure — I am dev behind this plugin :)
It’s edsy > Coriolis for me.
EDMC and/or EDD are must-haves too; EDSM/Inara/EDDB need all the help they can get, that information doesn’t appear on its own without your help1
There’s also https://siriuscorp.cc/edsa/ – this is a mirror as the original page is no longer up. Can be used to visualize weapon layouts and as a result, the convergence of different ships.