My Tasks screen shows you a list of all your open tasks.
On this screen you can:
Start tracking an existing task: Click on the play button next to the task name.
Set Priorities: slide your tasks to the left and select a flag colour to prioritize that task
Set due dates: slide your tasks to the left and tap on the calendar icon to select a due date
Mark a task as completed: slide your tasks to the left and select the tick icon to mark it as complete
Also you can use filters to sort your task list. You can sort them by priority, date, project, client or view your closed tasks.
Tap on a Task to access the Task detail. This screen shows you your to-do list, comments and time entries (activity) asociated with that task. You can edit your task from this screen too.