Free animation apps

[Podshell]

Does anyone on here use them? If so I have been trying in vain to find a simple to use one for a technical demo, but it is proving impossible! I thought it would be easy to find a clip of exactly what I want, all I need to do is animate a tumbling machine like device that is about half full or full of balls, but it needs to be in two dimensions so that the balls do not pass over or behind each other, think it is going to be easier to physically make something and fill it with hoops or discs such as coins and video it whilst it rotates.i have tried most of the top recommended apps but they are proving too difficult so gave up.

The app or whatever was used to create moving emojis may do the trick as I need it to play on a continuous loop if possible.

It's not an animation app per se, but capcut might be useful.

[Podshell]

Thanks will try that later, been looking through GIFs which seemed promising but still unable to find exact thing.