This is a quick note that I made for a class to have access to some reference links. I might expand on it later.
[edit: updated with moar links for another presentation]
Allows real-time device mirroring.
Hint: I don't think it's very clear, but you're downloading an installer. That means after you install what you've downloaded, you actually have to go to Applications and open Craft (the installer) to install for Sketch or Photoshop.
I use Sketch Mirror most of the time, but this does double duty of displaying prototypes as well as some "live" interactions that can't be seen in your screens due to embedded web content. For a ton more about this app, read their blog post.
Use this to install and keep track of all your plugins. I usually browse around or discover plugins elsewhere, but prefer to use the Toolbox to install them.
Older article, mostly to convince people about how great Sketch is. It also works as a decent overview of some features, but not exhaustive.
Sketch Keyboard Shortcuts
If you love getting into the shortcuts like I do, this is a decent list of all you need for Sketch.
Okay, just check out the author's page. He has a lot of handy ones. Aaron Tenbuuren.
Collections of Articles
Short articles about Sketch on Medium
Design + Sketch App*
Another collection of articles about Sketch, but these tend to lean more toward tutorials.
Pretty self-explanatory ;)
*Warning: try not to get lost in the template swamp. Steal a few good things, make them your own, and build from there.