Doit.im - Doit.
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.
TaskUnifier - TaskUnifier - Task Management Application
TickTick - TickTickis a cross-platform to-do list app & task manager helps you to get all things done and make life well organized.
The Hit List - Your life is complicated, but managing it doesnt need to be.
Conqu - Conqu is a simple yet powerful task management tool designed to help you conquer your inbox and get things done.