Have you ever wanted to get a closer look at something on your iPhone screen? In many apps like Safari, you can pinch to zoom in, but other apps don't offer this feature. Nevertheless, you can magnify any part of the iPhone or iPad screen if you enable the Zoom feature. This is designed to be one of the iPhone's accessibility options for the visually impaired, but anyone can use it.
Turning on Zoom
There are two ways to turn on (and off) zoom. First, you can go to Settings --> General --> Accessibility --> Zoom and then turn it on. That works fine, but those are quite a few menu levels to have to go through to turn the feature on and off.
Second, you can create a shortcut by going to Settings --> General --> Accessibility --> Triple-click Home. On this page, you can tell the iPhone what to do when you triple-click the Home Button. The default option is Off, but you can select the last option, Ask. With that option selected, any time you triple-click the Home button, a menu pops up that gives you three options, with one being to Turn Zoom On or Off. If you plan to turn Zoom on and off from time to time, enabling the Triple-click function will save you a lot of trips to your Settings app.
Come on and Zoom, Zoom, Zooma-Zoom
Once Zoom is enabled, you activate it by double-tapping on your screen with three fingers. By default, that magnifies 200%. If you want a different amount, you can double-tap three fingers and then drag up or down to adjust the magnification between 100% and 500%.
When you are zoomed in, you can still use all of the normal iPhone gestures such as flick, pinch, etc. Of course, you can only see a portion of the screen at a time. To pan around the screen, hold down three fingers and then drag around. When you are done using Zoom, double-tap with three fingers to go back to 100%. Thus, you can quick jump between normal and zoomed in by double-tapping with three fingers.
I would show you a screen capture to give you an example of using Zoom, but an iPhone screen capture takes a picture of the entire screen, even if you have magnified a part of the screen and cannot see the whole thing. Thus, a screen capture gives you the same image, regardless of whether the screen is being viewed at the normal 100% or at 500%. But here is a picture from Apple's website that gives you a sense of Zoom at work:
Because Zoom is part of the iOS operating system, it works on all apps. Thus, even if the developer hasn't included a pinch to zoom function, with the Zoom feature you can do it yourself. Zoom works on both the iPad and the iPhone, and I actually find Zoom more useful on the iPad; the screen is so large that you can enlarge one part but still see enough of the rest that you don't lose your sense of the screen as a whole.
I suspect that Zoom isn't a function that you are likely to use very often, but it is nice to know that it is there when you need it.