Autodesk ForceEffect is a free app available for Apple iPad and iPhone from the iTunes App Store that allows engineers including structural engineers to model and simulate concepts.
Real time solving capabilities provide immediate feedback on the performance of a design, enabling you to bring engineering to the point of the problem.
The version 2.0 brings a set of great functionalities. One of them is ability to add a load evenly distributed along an existing element at any angle. Thanks to this you will better simulate conditions like snow on rooftops or wind loads.
Find out more on ForceEffect http://itunes.apple.com/