What is it? Parker's have long been the bastion for car price regulation. Sounds boring. But just think how much fun all the extra money knowing a car's true value can bring. This app does exactly that with great ease.

How does it work? Simply chose the car model, make and year and you can compare up to 16 vehicles. It even accounts for mileage and modifications. Add the fact that it outputs second hand value (at varying levels of car quality), part exchange price and dealer value and you're set to buy or sell.

Why's it good? Never get overcharged again. Become the master of car sales. no more dodgy dealers. Well, it can't check the quality of the car you're buying, but at least you won't pay too much before the engine drops out on the way home. 

Where? Apple App Store
How much? £2.99