Jonny Evans, writing for Computerworld, digs through iOS 11 for all the new shiny. A good list.
Though there is a lot of great stuff to choose from, my two favorites are ARKit (which I write about a lot) and Siri Translate.
If you have the iOS 11 beta installed, give Siri Translate a try. For example, tell Siri:
Translate where is the nearest train station into Italian
Siri will present the translated text, and then speak the translated text in Italian. There’s a play button, so you can play the translation over and over again. Gives you a chance to work on your pronunciation or to play with audio for a native speaker. I do a lot of traveling, and this is like magic to me.
There are still a few glitches, but this is incredibly strong work for a new feature, let alone a beta.