Great question to follow, My favorite is LinkedIn app which i use for following the content of my interests.
Got to be onenote for me. Keeps everything handy in a single spot around all devices
OneNote and GLIP
Slack is my primary mobile app that keeps me in the mix.
Trello Alexa WhatsApp
Ride hailing apps
Pulse of course :)
As I travel a lot, I couldn't be without Citymapper for getting around a city.
One more app I enjoy while driving or traveling is Ubook. It is a subscription for audio books but you can listen to as many books as you want instead or a monthly credit.