Finally found an app which supports multimedia epub3 format. epub3 allows the reading (text) to be synchronized with listening (embedded mp3 of a human reader). This is much better than the text-to-speech (TTS) found in other ereaders. TTS relies on the robot voice, lacking the dramatic impact of a human reader, not to mention questionable pronunciation of some words. I haven't tested it with embedded video.
Highly recommend, even if you use it only to supplement a newer ereader. Also, the software was developed under FLOSS (Free/Libre and Open Source Software). So it's ...well, free!