Here are my favourite tools (web application, commercial, and open source software) that may have affiliate links:
Atom (text editor)
Brackets (text editor)
Skitch (screen capture)
ImageOptim (image optimizer)
Zipeg (open ZIP and RAR files)
Screaming Frog SEO Spider (Mac and Windows)
Snapseed (photo editor)
Pcalc Lite (calculator)
f.lux – adjust the light setting of the screen (FREE)
Launchy – program launcher (Windows, FREE)
HandBrake – video converter (FREE)
Onto to you.
What are your favourite tools? Let me know.