Sunbird is a Firefox addon for syncing calendars.

timeEdition helps you can see detailed documentation of your working hours.

HyperDock for Mac lets you take a quick look at the windows you have open in each program when you hover over icons in the Dock.

Fantastical is the calendar app for Mac.

QOwnNotes is a free open source (GPL) plain-text notepad with markdown support and todo list manager for GNU/Linux, MacOS and Windows, that (optionally) works…

BusyCal is a calendar app for mac.