The coast is clear

'The coast is clear' means that whoever you were hiding from is now gone.

Example:
-Has he gone yet?
-Yes! The coast is clear!

On the same page

Being 'on the same page' is a phrase used by one person to reassure that the listener is in agreement with them about something, understands or is thinking about something in the same way. It is usually used after there has been some discussion about something and an agreement has been reached.

Examples:
Okay, let's make sure everybody is on the same page. We'll meet back here tomorrow at 2:30 for rehearsal.

-Carol really needs to go to the doctor tomorrow. I think we're all on the same page about that.