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.
myOpenLab - MyOpenLab is a platform for finished elements (program components) that can be linked together.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Challenged - Create and participate in video challenges of any kind.
Slack - A messaging app for teams who see through the Earth!
The Monthly Challenge App - Join collective challenges, set your own targets and track progress.