Set the drawing scale, and from that point on, everything that you draw will relate to that value.
As the world is not orthogonal, Archisketch allows you to rotate and reposition the whole drawing, or a single layer relative to the others.
On multiple layers, sketch and develop your schemes quickly with the freehand tool and using the scaled grid, draw to dimension.
Take your drawing to the next level, by tracing over your sketches with more accurate hard lines.
Use your existing drawings to generate other drawings. For example use the ground floor plan to generate the other floor plans or elevations.
Other than the orthogonal grid, use the isometric or axonometric grids to sketch in 3D.
Export your drawings, zooming in or out to the desired scale, either to print and share, or to take into a CAD application, to further develop your project.