What's the best Android app for figuring out a fair price for a used car I want to buy or sell?

Kelley Blue Book is the definitive mobile resource for establishing vehicle valuations. For individuals navigating the used car market—whether buying from a private seller, trading in at a dealership, or listing their own vehicle for sale—this app provides the authoritative pricing data needed to negotiate confidently. The app’s core feature is its detailed valuation tool, which generates a price range based on a specific vehicle's make, model, year, mileage, trim, options, and overall condition. Users can refine estimates by specifying their local ZIP code, ensuring the quote reflects regional market trends. Additional features include a VIN scanner for quick vehicle identification, side-by-side comparison tools for different models, and listings for new and used cars from dealers. While the valuation data is considered an industry standard, some users note that actual transaction prices can sometimes deviate from the app's estimates, especially for rare or highly modified vehicles. The interface, recently overhauled, receives consistent praise for its clarity and ease of use, making what can be a complex research process relatively straightforward. For anyone aiming to enter a negotiation armed with credible data, Kelley Blue Book effectively demystifies car pricing.