The app shows eval bar during the game??

I just noticed that the app has an eval bar with each move during analysis and you can clearly use it for winning play.

No different than a coach whispering in your ear that you are playing correctly or bad.

The eval bar moves after each move when the game is in progress!??

Imagine playing a game and after each move you get an assessment of how efficient it was.

I was playing over my current games that are still going and the eval bar is moving after every move.

It's not showing me any potential move but it's letting me know if my previous moves are bad or good.

Anyone could look at this and use it for an advantage.

Is correspondence play like this?

I must be wrong about something.