Answer:
I am a type of weapon for SCI-FI characters
You write on me and secrets I can keep in places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?
I go in hard, come out soft. Blow me hard and I'll make a pop. What am I?
I follow you all the time and copy your every move but you can't touch me or catch me. What am I?
So simple, that I can only point. Yet I guide men all over the world.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.