I saw that powder game has some interesting tools, so i'm suggesting this. Remember the "wheel" from the powder game? We could use it here. 

Wheel. Spins elements and creates little wind 

-It turns wood into dust, ice into snow, and brck into stne.

-It turns if any non-solid element other than bray and ligh is touching one of its sides, unless the side that      

  it's touching is exactly on the top or bottom. It creates very little pressure when moving. It also turns with  

  pressure. (2+ pressure)

-It moves any powders, gasses, and liquids that are within its radius, but cannot be moved by any object.

-It cannot be destroyed in any way other than with wall erase.

-It could be created in 4x4 spaces like streamline is; it's a wall element.

-The maximum number of wheels that can exist on a screen at any given time is 100.

usage

-It could be used as a working turbine and power indicator that actually turns in place (not a moving solid

  that moves across the screen). 

-Wheel is sometimes used as moving decoration: for example, as airscrews in helicopters.

-It can also be used to show air flow.

-Wheels can be used to make power plants (hydroelectric, fusion, electrostatic etc.)

-Wheels can be used as a woodchipper, by allowing wood to "exist" through a spinning wheel to create dust.

Water turning wheel.