Go into Tasks.

Click on the task you wish to start and once you have clicked on it, a menu will open which will allow you to add the description of the task and make comments.

There is also a green circle on the top left corner of the drop-down menu. When you click on it the first time, it will update the status to say it is in progress. When you have finished the task, you click on that circle, and it will update the status to complete.

To undo it, if it was clicked on accidentally, you would just have to click it one more time for it to go to complete but click again soon after for the progress to be restarted. 

Or you could click one of the buttons that provides the timeline of whatever task you would like to check the progress on. 



Once you click on the button shown in screenshot above, it will go to a page which shows the timeline of when the task was created and will show when it's completed. 

Then double click on the task you want to update and it will bring up a screen allowing you to update the progress with the bar shown in the screenshot below, and you just have to drag the circle to the stage you are at with the task. If you want to undo the progress you can move the circle back to ''Not started'' if it was moved accidentally or move it back to ''In progress'' if it had been moved to completed when it hasn't been.