Slide-over is a new feature you'll find on your iPad shortly after updating to iOS 9. In a bid to increase the multitasking capabilities of its tablet lineup, Apple is adding features that make it possible to do more than one thing on your iPad at a time.
Accessing slide-over is simple; when using an app, slide your finger in from the right edge of your iPad's screen. A small panel will slide out along with your finger, revealing a column of app icon. In the event an app is already open, you can slide your finger down from the top of the slide-over panel to bring up the list of apps.
Tap on one of the icons to launch the app in slide-over. Notice you can then use the app as you would if you were using the app in fullscreen mode. When you're finished, just slide the left-edge of the slide-over panel to the right to close it or tap outside of the panel.
Currently, only Apple apps are working with the new feature. However, once iOS 9 is officially released, developers will have the ability to release updates to apps, adding slide-over compatibility.
Which leads to one big problem with the feature: You cannot disable or remove apps from showing up in slide-over, meaning the column of apps is going to get rather crowded. Hopefully Apple adds the ability to remove apps (or developers include the option within their own apps).
reading•How to use the iPad's new 'slide-over' feature in iOS 9
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