Mac: Diagnostics utilities don’t really need to be feature-packed. In fact, since their main purpose is to give you information about a busted Mac, it’s actually best if they’re very simple. EtreCheck fits that bill.
EtreCheck collects a ton of statistics about your Mac. This includes your hardware, software, installed apps, kernel extensions, and just about anything else that can cause your Mac to stop working. When it’s done collecting information, EtreCheck gives you a simple, text-based report of everything it learned so you can easily send that info to someone for help (or troubleshoot your own computer). It’s a super easy way to figure out what’s going on with your Mac without running any complex utilities.
EtreCheck (Free) | via Macworld
EtreCheck Produces a Bare Bones Diagnostic Report of Your Mac