Ok, I use YNAB for my budgeting, I set it up at home, and then there are iPhone and android apps to keep track of what is budgeted, and what is available. It syncs through drop box. To limit her spending, I just opened an account at the local credit union, and deposit what she is allowed to spend. And as you said, anything left over at the end of the budget period, she keeps half for blow money. It has worked well for us, and she is much more cognizant of her spending.