You don't need rulers or snap on grid as it's obsolete feature in professional CAD software. BabaCAD 2017 has advanced "Dynamic input" feature, so it's very easy to draw anything with measure. Just start to draw lines/polylines and enter length, distances and angles using dynamic input which is turned on by default. There are also object tracking (tracking lines for horizontal/vertical, orthogonal and extensions on lines that you draw). BabaCAD has object snap on nearest, orthogonal, intersections, extensions for advanced precision drafting.