This is Chrome Remote Desktop and it’s fiddly to set up unless you’re already in to the Chrome browser. But once it’s running, it’s remarkable how well it works and what it does:

Imagine squeezing your retina iMac screen down onto an iPhone 5. You can do it. It might look a bit silly, and initially you might wonder why you’d bother, but it has long been possible to see and remotely control your Macs and PCs on even your iPhone. Now that Google has released Chrome Remote Desktop for iOS, you can do it for free. You’ll do it, too: try this once, and you will forever keep finding other reasons why it’s incredibly useful.
It’s fantastic when you forget a file, for instance, and can now just find and email it to yourself from afar — and it will save your soul, your sanity, and your gas money when you are supporting several family members who live halfway across the country. Just open up your or their Mac’s screen on your iOS device and work as if you were right there in front of it.

Hands On: Chrome Remote Desktop (OS X, iOS) – William Gallagher, Electronista (19 January 2015)

Read the full piece.