Design Milk reports: [edited]
Archipad is a new iPad sketching app by Urban Design that is scale aware. Once you set the scale of your drawing sheet, the drawings will be completely scaled to the real world, even down to the line thickness.
In addition, Archipad has many other features that cater to architects and designers, including layer rotations, shape and freehand drawing tools and more. It has a tiered pricing structure, it’s free to download for small projects. As projects become more complex, the user can buy a subscription for however long or short they need the app for.