A smarter Rectangle tool with added snapping and anchor point capabilities.
Rectangle - Dimensioning according to anchor point
The app adds an anchor point to the rectangle depending on its type. It allows you to resize the geometry relative to the anchor point (marked with an X).
Rectangle - Disconnect points
To use the sides of the rectangle separately, just select one of the endpoints and hit disconnect.
Rectangle - Align by center points
Use the new center points to snap rectangles to other sketches.