Using this free app, download high-resolution 2D maps of 750+ resorts to an iPhone or iPod Touch. No signal at 12,000 feet? No problem. The maps are stored on the device, so they’re always available. Using the ad-free, $4.99 version, download 3D maps from resorts in 35 states and around the world. GPS tracking records vertical feet and distance skied, which can then be uploaded to the web and Goggle Earth.