10-4 by WEX is a free Android application designed specifically for truckers, independent owner-operators, and contractors to help them save on diesel fuel costs. The app allows users to pay less at participating truck stops across the nation and offers rewards for additional savings. With no credit checks or transaction fees, it provides a straightforward approach to managing fuel expenses.

The app features a fuel finder that helps users locate discounted diesel stations nearby or along their routes. Payments can be made securely within the app using a credit or debit card, and users can activate pumps with a secure fuel code. Additionally, users can earn rewards for every gallon purchased and for inviting friends, making it an effective tool for maximizing fuel savings and tracking expenses.