See inside to start animating!!!! In the code there are variables you can set such as: • The frame rate • The frame where the animation should start • Whether you want your animation to be looped (1 = yes, 0 = no) I recommend not to set frame rate over 29, as frames and sound may be likely skipped due to scratch's 30 fps cap Each costume in the "Animation" sprite represent a frame in the animation. You can set the length of a frame by setting the name of the costume to something like this for example: "_2{whatever costume name}" This will make the frame length 2 for that frame and would play it for twice as long You can play a sound at a frame by giving the sound the same name as the costume representing that frame For onion skinning, you can use the onion skinning addon from the Scratch Addons browser extension Oh, and you can duplicate the "Animation" sprite too for more layers, elements or whatnots.
This should also be playing synchronized on any device (Though frames and sound may be skipped if laggy) You can credit @Toad_85 if you used this