I have already blogged my thoughts about this topic on the US History Teachers Blog. If you want to stick with your existing PowerPoint presentations, you can make them interactive by uploading them to nearpod and then your students can watch them on their devices and respond to questions that you embed.
If you want alternatives to PowerPoint entirely, you can make presentations with either prezi or emaze.
But this presentation package was entirely new to me. It's called PowToon. PowToon's banner says that "It's free and it's awesome." I concur as to both.
PowToon makes animated videos and presentations. I could write paragraphs describing what it does but it would be much better for you to see two short examples. Both were created with PowToon.
Powtoon is ideal for those seeking a nice alternative to more traditional presentation tools. Simple to use, it makes creating engaging, interesting, and exciting animated videos extremely easy. Users can create and show presentations straight from the Powtoon site, or opt for the export to Youtube option, or even download a MP4 video format for use offline.PowToon has a set of tutorials on its QuickStart Guide page. I also like this tutorial (6:55).
The PowToon animations are so cool that I will be assigning them to my students to use. Why should I have all the fun?