Autodesk FormIt

This mobile app helps you capture building design concepts digitally anytime, anywhere ideas strike. Use real-world site information to help create forms in context and support early design decisions with real building data. Experience a continuous Building Information Modeling (BIM) workflow by synchronizing designs in the cloud for further refinement using Autodesk Revit software products and other applications.

https://itunes.apple.com/us/app/autodesk-formit/id575282599?ls=1&mt=8