Can I install YouTube, xfinity, Netflix or sling on an ipad2?

Yes, if you have an iPad with iOS 12

No, if your iPad is old with iOS 9.3.5.

Note those are 3rd parties app, best you visit their websites.

YouTube:

Compatibility Requires iOS 10.0 or later. Compatible with iPhone, iPad and iPod touch. Apple TV.

Netflix:

Compatibility Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch. Apple TV.

ckuan may not be completely correct.

You maybe able to Install an earlier version of Netflix.

Google YouTube no longer supports earlier versions of their YouTube app for older iDevices and older iOS versions.

So, you would need to use the YouTube Website, instead of the app.

Not sure about Xfinity or Sling TV.

If you own a newer iDevice and/or own a real computer.

Older versions of apps may still exist in the iOS App Store, despite the fact the apps may have moved on to an higher minimum iOS version, now.

If you need older versions of apps that have moved on to iOS 10 and later, tap on my link below and choose the method that best works with your current situation.

CAREFULLY read and follow ALL my directions. Especially so for my computer/older iTunes procedures.

Any and all three of my procedures/solutions work!

Downloading Older iOS 9.3.5 Versions of A… - Apple Community

A Disclaimer.

Apps may or may not have older iOS 9.3.5 versions still available from within the iOS App Store.

The Netflix app has older versions of their app, in the iOS App Store, that go all the way back to iOS 5.1.1.

There are three ways to try/attempt to get an older version of an app. Pick the method that works best for your situation/circumstances.

Also, I would STOP using that nearly 3-year old Safari web browser, as it is, probably, not safe and secure to use any longer, and seek out a third party web browser that is STILL currently being updated and STILL being supported on iOS 9.3.5.

Heed my advice on this issue in my above link.

Best of Luck to You!