Something I think could be useful is a budget calender based around individual pay months. You would be able to populate any events you have over the month with estimated spend to help give you an idea of the remaining balance and if you can actually afford it! The money could be held in a goal and released on or around the date required.
It would help me budget better for the month and once populated, on the days where I’m not doing anything show me an average daily budget I could safely spend.
It could possibly integrate with Google calendar/iCal for ease too (not sure of privacy there).
What do people think? Would this be useful to you?