macOS

Useful utilities

• KeepingYouAwake - lightweight wrapper around caffeinate command
• Rectangle - lightweight window tiling utility
• Stats - menubar gauges

Gaming

• Steam - native Mac version, quite a few games have native macOS builds
• CrossOver - the most complete package of compatibility layers for Windows games
• Whisky - discontinued, but free UI for Wine and Game Porting Toolkit

Development tools

• Kaleidoscope - excellent diff app that, unfortunately, adopted subscription pricing
• Tower - Git UI, probably the best on the market
• Fork — another Git UI, close to Tower, ships with a good diff viewer. Available for both Mac and Windows with an endless free trial