Use urgent/important instead of priority 1,2,3,4
Could be a nice feature to categorize tasks by labeling them as (urgent, important), (urgent, non important), (non urgent, important),(non urgent, non important).
see Einsenhower Matrix representation.
see for instance http://www.bairdscmc.com/2013/04/the-eisenhower-matrix/
This way to prioritize tasks helps a lot to see clearly what needs to be done.
You can get this on sandglaz.com