You might not need one every day but now and again, a magnifying glass can certainly come in handy, say to read the small print, check for ticks or look at a scratch in some furniture. Few people have one to hand, though, which is why the app on the iPhone or iPad is particularly useful – turning the devices into magnifying glasses. The Magnifier app is pre-installed on every iOS device that has a rear-facing camera. The fastest way to find it is to use the Spotlight search, which you access by swiping down on the home screen. Enter “magnifying glass” and tap the icon that appears. Hold the iP…