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.
Astral - A social network for augmented reality 📍
Nifty - Manage projects, work, and communications in one place.
Azendoo Task Pilot - Task collaboration for teams 🚀
Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.
Proj.email - Manage projects via email