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.
CAMPR - Open source project management tool with 16 modules
GoodGantt - The best Gantt chart for Trello®
Confleo - Confleo is an all-in-one project management and CRM tool that allows you to create and manage multiple projects, assign multiple users within it, create stunning invoices for your clients and even accept payments from them through in-built payment g…
Paws for Trello - The best way to use Trello on your desktop
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.