A buddy of mine wrote this app, see the link below.
Pretty much all it does now - it asks you few questions about your lease terms, like how long is it, when did it start, how many miles, and what’s the charge for every extra mile. It only asks that once, and after that every time you open this app - you need enter your current mileage, after you do so - you will get your statistics, such as how many miles you have left, how many days you have until the lease is over, what’s the recommended amount of miles per day to not exceed your lease terms, and if you already have exceeded your lease miles limit - it will tell you how much you will get charged for the extra miles you currently have.
So, as I said it is really simple, and small too. And it doesn’t send your data anywhere. But the main point that I am trying to make here is - comment on this, and suggest your ideas of what else you would like to see in the app, and I will let my buddy know, so he can add these features.
Oh and it’s free.