-allows user to move particles within the pen borders around.
-of course it would not be able to move solids or attributes (such as heat and pressure).

I find it somewhat annoying that I either have to pause and create a substance somewhere or build an elaborate ramp system just to get a particle to move sideways.

Also for Tools:
GRVO (Gravity Orientation)

-a single, placeable particl on the border only that changes the direction of gravity in a single direction (Ex: On the right side of the screen for gravity falling to the right.)

And a setting to make particles not disappear at the edge of the screen (Like how life particles can teleport to the other saide at the border.)