Do you have tasks that need to be done every so often? Maybe you want to change your furnace filter every month on the 1st. You could schedule a recurring appointment on your calendar, but if you don't complete that task right away then you will be out of sync with your calendar. For example, I get the reminder on the January 1, but don't change the filter until the January 14, I'll still get the next reminder on February 1 which now is too soon, because I always want to wait 1 month from when I actaully change the filter. It's tedious to have to edit my recurring appointment every time.
So, this is a different approach to recurring reminders. It's a recurring todo list which provides the abilitiy to set how often you want that task to come back after you check it off the list. The timer starts when you check off the task. For example, I would schedule a task to change my furnace filter with a recurrence of 1 month. When I finally get around to changing the filter and check off the task, it will stay checked for 1 month. After that, it will come back on my todo list and provide a notification. So when I finally change the filter on January 14, it won't remind me again until February 14.