What's the best iOS app for checking mountain road conditions and chain control requirements in California?

Caltrans QuickMap is specifically designed for navigating California's complex mountain roads and winter driving conditions. The app excels at providing detailed information about chain control areas, road closures, and accident reports that help drivers make informed decisions about their routes. Users consistently praise how the app displays precise locations where chains are required, along with real-time traffic camera feeds showing actual road conditions. For anyone driving through Sierra Nevada passes or coastal mountain ranges during winter months, this information can be crucial for both safety and trip planning. The app also includes detailed accident reports that indicate severity and estimated clearance times, allowing drivers to choose between waiting, rerouting, or continuing. While the interface isn't particularly flashy and some users note occasional loading delays in areas with poor connectivity, the accuracy of the road condition data makes it indispensable for California mountain travel. Reviews indicate the app performs reliably even in remote areas where cellular service is limited, though downloading maps in advance is recommended for the most consistent experience.