Docollab is described as 'collaborative workspace for teams. With Docollab you have a single place where team members organize, view and edit files, and assign tasks and track their progress' and is an website in the Office & Productivity category. There are more than 100 alternatives to Docollab, not only websites but also apps for a variety of platforms, including Windows, Mac, Android and iPhone. The best alternative is LibreOffice, which is both free and Open Source. Other great sites and apps similar to Docollab are Joplin (Free Personal, Open Source), Google Drive (Freemium), Google Keep (Free) and Trello (Freemium).
Passfindr is a web based premium Personal knowledge base, Password manager and Bookmark manager application to securely store passwords and other sensitive information in a virtual vault locked with individual master passwords.
Once enabled, a new Tasks menu will appear in your Nextcloud apps menu. From there you can add and delete tasks, edit their title, description, start and due dates, reminder times, mark them as important, and add comments on them. Tasks can be shared between users.