As mentioned Muvizu is one of a kind within this field as it offered actual 3D scenes, characters, and props. You can also import your own 3D elements into a scene. Motion tracking is easy, 3D camera operation, lip-syncing, and many more features. You don't have to be an animator to build your first scene in minutes.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Plotagon - This app, Plotagon. is very fun. Creative and lets me express my ideas and all of my desiors!
Celtx - Celtx is a scriptwriting software platform with applications in a wide range of mediums but that specializes in helping screenwriters.
FaceRig - FaceRig is a program that aims to enable anyone with a webcam to digitally embody awesome...
Trelby - The free, multiplatform, feature-rich screenwriting program!
MocapX - Facial Motion capture app Maya and iPhone. With the MocapX animator, you can easily use the iPhone camera to animate characters in real time directly in Maya. MocapX tools enable you to use any custom or production rig as well as any Maya feature.