MyDraw provides many aids that aim to make it easier for you to draw geometries and place shapes at exact coordinates.
These aids include the guidelines, grid, and rules.
Guidelines are user-defined and can help you arrange shapes and other drawing primitives more accurately.
The rulers operate in the current drawing scale, thus giving you exact measurements of the objects that you work with. For example, if you are creating a floorplan the rulers will show you a table measured in feet, not pixels.
The grid is displayed behind the objects that you draw, thus naturally helping you to more accurately place, align and resize objects.