Remember how with iOS 10 you could integrate social media apps like Twitter and Facebook? Well with iOS 11 — simply put — you can't.

You now have to manually allow access within each app that asks for it, meaning that direct integration with apps like Twitter, Facebook, Flickr, and Vimeo.

Rather than continue to add support for different social services, Apple went with a different approach, adding sharing extensions with iOS 8 in 2014. Until now, it has maintained the single sign-on for Twitter and Facebook in addition to supporting the sharing extensions for a wider range of apps. (Axios)

So what does this mean?

Twitter, Facebook, Flickr, and Vimeo will now be treated just like regular apps. You can see the difference in what your settings look like between iOS 10 and iOS 11 with this screenshot from MacRumors: