What is the best reader android to open a EPUB3 with interactivity?
Try Infinity Reader for Android from Google Play https://play.google.com/store/apps/details?id=com.imeonsoft.infinity . The reader supports audio, video, scripts and all EPUB3 features. The reader comes with a free book, which contains youtube video.
You can download a lot of free books from the reader.
I use Readium(Chrome plugin) for Windows and Mac