Grading the importance of tasks

I like the simplicity of this app. I only miss one feature: marking important tasks. It’s similar to bookmarks, only easier to mark and unmark. It would be nice if it had a 1-3 or even 1-5 scale for importance. The results should be displayed in a column next to the list of folders and bookmarks.
With a large number of tasks, it would be helpful to plan the next job.