Because they follow the traditional pattern of presentation packages, LibreOffice Impress and Caligra Stage should be fairly easy to get the hang of, especially the latter program since it’s the most similar to PowerPoint. Google Slides, which also follows this pattern, should also be fairly easy to use although there’ll be a bit more to learn about because it has additional features for collaboration.
Turning our attention to Sozi, we can’t look at the application in isolation because the complete process also involves creating the base poster before you start to animate it. This means that the ease of use depends also on how skilled you are with a good vector drawing package – Inkscape, for example. Regarding Sozi, though, we do have to admit that it’s not as easy to get to grips with as the likes of LibreOffice Impress or Calligra Stage, although that’s due to a large extent because the concepts aren’t as familiar.