SavvyCal - A scheduling tool both the sender and the recipient will love.

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.

Calendly - Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.

Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.

What Time Today? - Open source Calendly alternative

Corrello - Dashboards for agile teams using Trello