Line that indicates where I am - exactly - in the timeline

[El Wombat]

When editing a certain bar in the timeline, there should always be a vertical line indicating where I am, exactly, in the timeline.

For example, when fine-tuning hand movements, that would make it easy to synchronize them with a certain viseme, i.e. mouth position, so as to accentuate accurately.

Basically, that same vertical line as in use in other apps like Pr.