This one is for all you app designers! Skala View is brilliant at previewing designs at specific zoom levels and at fitting your design to the display, for situations where size is more important than pixel accuracy. There’s also 25%, 50%, 66.66%, 75%, and 150% image scales. Just plug your iPhone or iPad into your Mac and you’re connected, because USB is faster, more reliable and easier to set up than Wi-Fi. Want to preview your design with a white, black or no status bar on iOS? Done. Using a live, real status bar means you don’t need to include a fake status bar in your design. It’s even possible to view different colour blindness testing, orientation or zoom levels on multiple devices at once.

Get it for OS X or iOS or Android!