Use the Budget iPhone webapp to monitor your daily, weekly or monthly spending. Set yourself a limit and debit all your payments. You can always see how much money is left until your budget is gone and whether you might better postpone a purchase. Over time this should help to to save some money instead of going into dept. Try with TestiPhone
I have researched into many different finance apps, and I like this one the best. The main reason (which budget doesn’t seem to be advertising very cleraly) is that you can use this to sync budgeting and expenses between multiple iphones, so my husband and I can enter in our expenses and then sync with each other so we’re both on the same page. Easy to edit and shows budgeted vs actual spending. very nice design!