(I’m publishing this post again because I included an incorrect link to Mixercast in the original version. Sorry)
In order for such an application to work easily for my English Language Learner students and for me, I think that such a slideshow-maker has to meet three criteria:
1) The interface is relatively simple to understand.
2) It’s easy to use pictures from other Internet sources so we don’t have to deal with uploading photos from school computers.
3) Students have a place to write about the slideshow itself in the presentation.
Unless I’m missing something, which may very well be the case, I have only been able to find one slideshow maker that meets all three criteria —MixerCast I’d encourage you to check it out. Registration is quick and free. It’s one of the links in the Student Slideshow section.
While you’re at it, though, it’s also worth checking-out the other Student Slideshow links I have in that section. They’re all good, not just as accessible to English Languages as Mixercast.