In order to get a clear view of what a single purchases actually cost you in terms of working time.
You simply save your monthly income and hours worked in the app and each time you want to make a purchase you enter the amout you are about to pay and it converts it to working hours and minutes. Ex. a lunch might cost you 33min of working time and that new gadget actually costs you 46 h of working - is it worth it? You decide of course, but you have a clearer view of what the true cost actually is!