I found this list of 25 free macOS apps every Mac user should have, which I found on my twitter feed, interesting.
I already use some apps like Wunderlist, Slack and VLC mentioned in that list. But one app that I felt I could use is Itsycal. It shows the calendar from the menu bar; something I wish the default time date / time app on Mac showed. Itsycal also connected to the calendar app on the Mac and synched all the events. I am no longer using the default time app on the menu bar. Now my calendar is just Ctrl + I away.