Sketch Mirror is a companion app for Sketch on the Mac and was built to let you preview designs from the Mac on your iOS devices over Wi-Fi.
You can swipe on your device to switch between pages and artboards in your document and zoom to inspect individual pixels. What's more, Sketch Mirror scales your designs up or down to fit the screen resolution of your iOS device automatically.
Also, you can run Sketch Mirror on any number of iOS devices and connect as many of them as you want to one Mac client. Preview your iPad-sized artboards on one device while your iPhone or iPod Touch mirrors the smaller artboards.
Sketch Mirror was built as a companion app to Sketch on the Mac and requires it to function.