Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Papermerge DMS - Open source document management system designed for archiving and retrieving your digital documents. Instead of having piles of paper documents all over your desk, office or drawers - you can quickly scan and upload them to Papermerge DMS.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Paperless - Developers and publishers of Mac, Win, and iOS productivity, home and office and writing software such as MacGourmet, Paperless, MacJournal and many more. Based in MN.
Slack - A messaging app for teams who see through the Earth!
Paperless-NG - A supercharged version of paperless: scan, index and archive all your physical documents - jonaswinkler/paperless-ng