So I created a simple animation with 2 scenes. I can play and pause the entire animation but I want to be able to pause at specific frame number. Any idea?
You can do it manually by play-pause where you want.
or
Copy paste this code and hit Return to Ruby Console:
Sketchup.active_model.pages.show_frame_at(1.8)
Where the number in a brackets is a relative time to frame where you want to go (in seconds)

Source:
The #show_frame_at method is used to show a frame in animation (of the slide show) at a given time in seconds.
I already tried that but the animation is faster than my hand and by the time I click pause, few frames already passed.
So there is not direct and easy way than this? How about an extension for this purpose?