Do I need a special app to use split view with IOS !1

What iPad do you have?

Full split screen multitasking is only available to iPad Pro Models, iPad Air 2 and iPad Mini 4.

Split screen mode within the Safari web browser, under iOS 10 & 11, may (or may not) work for other iPad models, but full multitasking is limited to the iPad models above.

The new 2017 iPad 5, for example, has the Safari Split screen capability, and, I believe, the Slide Over multitasking functionality ONLY.

Which iPad do you have?

You can use Split View with iPad Pro, iPad (5th generation), iPad Air 2, or iPad mini 4.

Use Multitasking on your iPad - Apple Support

Maybe you need all of this to help you properly learn to use and navigate iOS 11.

iPad User Guide for iOS 11 by Apple Inc.

https://itunes.apple.com/us/book/ipad-user-guide-for-ios-11/id1263310093?mt=11

Another very good iOS 11 Users Guide

https://arstechnica.com/gadgets/2017/09/ios-11-thoroughly-reviewed/

VIDEOS!!

iOS 11 Basics

https://www.youtube.com/watch?v=cnEfNBQ_F1Q&list=WL&index=81&t=904s

https://www.youtube.com/watch?v=_rgnwfgHXSg

iOS 11 Dock

https://www.youtube.com/watch?v=i2eXus8fweg

https://www.youtube.com/watch?v=MBoeJCmxnpA

iOS 11 Multitasking

https://www.youtube.com/watch?v=JsAh2EjyIVo&index=83&list=WL&t=8s

Good Luck to You!

No, split screen no longer works on iOS 11. I tested it on the iPad Pro, and it doesn't seem to work anymore.