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.

Mobilize - Mobilize is a scalable messaging app built for large groups.

Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.

Crew - Group messaging, tasks, and scheduling all in one app

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.