Say hello to Crystal, the only app you need to preview and prototype Sketch designs. Relied on by teams at Google, Apple and Expedia. Open Crystal on the same WiFi as your computer and start previewing your designs in realtime. Crystal refreshes on the fly as you modify your artboards in Sketch and auto-switches to your current Sketch artboard. If you're without WiFi or in corporate networks where Crystal can't find Sketch, USB support is provided with the help of the Mac companion app, available at https://crystal.smithy.productions/#companion. Live Prototypes🌟 Swipe between adjacent artboards or prototype using clickable elements to move screens. Crystal fully supports Sketch prototyping, including transition animations and Android back button navigation. Finally you can preview mobile app designs on the devices they're made for. Pixel Perfect📏 Crystal automagically™️ fetches scaled artboards, so that your designs match the pixel density of your device. Tablets are fully supported, and include the ability to view artboards fullscreen or at phone-scale. Download Documents💾 Easily save any Sketch documents to your device for offline access without Sketch. Untether yourself from your computer and demo your designs to others with full offline prototyping support. Note: Crystal is a companion app for Sketch and requires it to function. Trying to use it for anything else, like watching movies, playing games or browsing the web will probably result in a sub-par experience. Crystal is free for everyone. Unlock certain features and support development by subscribing.