Mac OS

Shortcuts:

Apps

Cmd + Tab = open previous app, jump back and forth between apps

Cmd + Tab (hold and hit again) = cycle through opened apps, see what apps are opened without moving your mouse to the dock at the bottom of the screen

Cmd + Tab (hold and let go), Shift + Tab (again while still holding Cmd) = like above, to cycle through opened apps, but this will cycle backwards, in case you hit tab too many times

Cmd + Q = quit app

Cmd + W = close tab

Cmd + H = hide app

Cmd + R = refresh page (this sometimes works in other apps than just the web browser)

Screen capture:

Cmd + Shift + 3 = capture entire screen (to Desktop)

Cmd + Shift + 4 = capture part of the screen (click and drag area)

Cmd + Shift + 5 = capture part of the screen (remember selected area for next time) This option will also let you set what folder to save the screenshot to (instead of saving to Desktop). This will permanently change it for options 3 and 4 also, so don't forget it! You can always hit this combination again to change the output folder, to change save location.

Also hold Ctrl during any of these to copy to memory instead of save to Desktop! Later you can Ctrl + V to paste the screenshot into a document or email!

Convert Video to GIF

ezgif.com - create GIF from Video (really useful for screen grabs), and vice versa. Other great GIF and image transformations.