Mannequin by Fabrication Games is designed for artists to study the human figure. The mannequin is fully 3D with chain-function moveable limbs allowing you to move them all at once or each individually. The 3D feature allows the pose to be set in realistic lighting to accurately highlight and shadow the form.
This app has the capability to automatically save the previous pose, undo and redo movements, reset the entire form, and also generate a random pose. When going on a field trip to sketch at the Cleveland Museum of Natural History or the Botanical Gardens, creative poses could be a fun detail to sketch into the scene. Mannequin is available for $2.99 in the iTunes app store.