Tatsu - Standup meetings for remote teams.
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.
List Bot - An SMS bot for to-do lists
Sendtask for iOS - Free, powerful & simple to-do app for teams & partners
Any.DO - The #1 task management app used by over 11 million people globally, Any.do is your free mobile and online task manager for Android, iPhone, Web and more.
Plan - Plan is a better way to organize.