A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate
in the Unity community.
Are there plans to add support for Android's BigPictureStyle, and iOS's Rich Notifications?
I restored a revision and found that I was missing files from the root project folder (the one that contains the Assets and Library folders)....
You can simply download an app from Google Play called "Device ID". Should take you less than a minute. It displays the ID and a few other things.