You can use AR with street view to put yourself in the middle of the action at the front of the British Museum in London. People undergoing renovations of a home, office, or another building can use AR to see what the finished product will look like. You can even use it to figure out how to work an espresso machine to get a perfect drink every time.
Google's been tweaking their AR tech quite a bit to provide as many different features and experiences for users. For example, users can desaturate and decolorize what is actually in front of you in order to draw focus to the AR parts of the experience. They've also been playing around with Google's VPS (Virtual Positioning Service) that allows you to take AR one step further, into the wider world.
If you're interested in seeing more of what people can do with ARCore, you can visit Google's website This Is ARCore, where they've highlight some of the most interesting and fun uses. My personal favorite? The guy who sends a virtual fire-breathing dragon to run after his poor sister.