Heron Animation is a free stop motion animation program that lets you take pictures from a webcam and assembles them into an animation. Is simple to use and has a clean and user-friendly interface, which make it perfect for beginners and more experienced animators alike.
It features: Instant playback, Onion Skinning, compatibility with a wide range of webcams, and export in MP4. MOV, AVI or individual frames.
here a quick screenshot with the “onion skin” feature

also available as Online App