Microsoft announced a few weeks back that Windows 10 would include a Phone Companion app, which would allow users to easily setup and sync their phone with their Windows 10 PC. The Phone Companion app works with Windows 10 Mobile, Android and iOS devices, and will be available in the Windows 10 RTM by default on July 29th.
When connecting your phone to your PC, the Phone Companion app recognizes that a phone has been connected, and will show detailed information about your phones storage and battery percentage. If your device is a Windows Phone, it will tell you that if you're using the same Microsoft Account on the phone and PC, then there's nothing you need to do and Windows is already syncing everything.
Those of you who have an Android or iOS device, the app will help you get your phone setup with Windows 10 by allowing you to email a download link to whatever app it is you're setting up with Windows 10, and will then explain what you need to do once the app in downloaded to your phone. Upon opening the Phone Companion, you get to choose either Windows, Android or iOS. The app will then help walk you through setting up your new apps on your phone.
Backing out before you finish setting up an app will leave the task 'In progress' for you to return to later, and apps which are not yet available on a platform are grayed out with 'Coming Soon' text within. Cortana for Android is coming as a Beta in July, and for iOS later this year. So unfortunately, iOS users will indeed be seeing the grayed out buttons for Cortana.
The Phone Companion app in Windows 10 will help millions of people setup and sync their mobile devices with Windows 10, whether those devices are Windows, Android or iOS based, the app works with all kinds of hardware. The Phone Companion app should show up in the next Windows Insider build, and first made an appearance in build 10147 which leaked recently. Unfortunately the app in that build is broken. Let us know below if you like the look of the Phone Companion app!