When you want to end your turn early, you click on an empty space and the menu comes up. On the bottom right it will say "Left:" and a number in green, and "Custom:" and a number in red. What do these numbers mean?

The green number will tell you how many units are still waiting to move. The red custom number tells you how many units have a custom auto battle command active. Took me a couple of minutes of monkeying around with the auto-battle function to figure it out since neither the in game guide nor the manual explains it.

@c2c: Thank you!