Having your User ID handy is very useful - it allows us on the Support team to find your account in our system!
This means we can transfer your game to a new device (on the same platform) or simply find your account so we can help you with your issue/question.
It's a good idea to go take a screenshot now, even if you're not planning on contacting us right away.
To get your User ID:
1) Tap the gear icon at the bottom right
2) Your User ID is displayed at the bottom - take a screenshot to attach it in an email to support!