Apple finally lets iPad owners use two apps at the same time in the iOS 9 update. There are three forms of iOS 9 multitasking on the iPad. You'll need the newest iPad to use two apps side-by-side, but the other options should work on older iPads.
Slide Over allows users to quickly open up a second app while leaving the main app open in the background. This is almost like an iPhone version of the app that you can quickly open to reply, message or reference something.
Split View is the full on multitasking with two apps on-screen at once. This allows users to work in both apps just like on a computer. When paired with a Bluetooth keyboard Split View delivers and incredibly productive work experience.
Picture in Picture allows users to pop out the video or FaceTime window into a small window that sits on top of the other apps or your home screen.
Developers will need to add support for these features, but on stage Apple announced that developers already did the hard work thanks to changes made in iOS 8.