This app offers itself to you for free for a limited number of drives per month - but more than 1 per day - so you may never need to upgrade to the paid version: "No buttons to push, no start or stop needed. MileIQ remembers your drives so you don’t have to. All it takes is a swipe. Give your drive a purpose, and MileIQ will tell you its value. With your mileage log literally at your fingertips, deduct or expense miles with total peace of mind. Try MileIQ for free and get 40 drives a month."