Within YouTube there is a free tool for creating audio slideshows. You supply the images and YouTube supplies the audio track. You can pick from thousands of audio tracks to match to your slides. After adding your slides and selecting an audio track you can add speech bubbles to your slides. I demonstrate all of these steps in the video embedded below.

Applications for Education

Creating an audio slideshow with annotations in YouTube is a good way for students to share the highlights of some basic research that they have conducted. Before YouTube offered this tool I had students use Animoto to create audio slideshow videos as biographies about U.S. presidents.