I get asked a lot about timeline apps. Books Creator has all the functions you need for an interactive timeline. However, if you use Seesaw and want interactivity you will need to share as PDF. Note only text and image will publish as a PDF. For many of us though, text and image is enough!
Of course iBooks with video and audio is great too, but this is about using two of the most popular apps in primary/elementary education and pushing some boundaries.