Creating shapes with stroke only

Hello!
This is absolutely possible to create shapes with just a stroke on Fresco, actually it's the "normal way" to create shapes, as filling them is an extra step (with the fill tool). It's possible with every type of brush. Two ways of doing it:
With the drawing aids:
press long on the ruler icon, and choose any of the drawing aids from there:

they will act as a French curves, you just follow along the shape to trace your circle/rectangle/polygon.

second one, the new "snap to shape"
create your shape in one single stroke and hold at the end of the shape. The stroke will then snap into a perfect circle/square/triangle, whatever.
You can set up the parameters by going to the cog wheel on top right of the interface, choose "app settings"> "input" and then scroll a bit to change the settings

Be sure to follow the in app tutorials (as seen on the home page), they're very helpful.

Hope it helps!