Time Train is a companion to Timelines of Everything, a big, beautiful book from DK that walks through history from the Big Bang to today, one two-page spread at a time.

I made this for my daughter. As we read the timelines together, we kept having questions and wanting to learn more, so I decided to create this companion. It pairs each timeline in the book with a short video that dives a little deeper into the topic.

We recommend reading the timeline in the book first, then watching the video that goes with it.

A few things I did to make it kid-friendly:

• It opens straight to the next stop, so there's nothing to scroll through or choose.
• The player is designed to keep taps from wandering off to YouTube.
• Videos stay muted until any ads finish and the real video starts playing.
• It's one video a day by default, and the grown-up settings sit behind a press-and-hold lock.
• Stops about harder parts of history are flagged, so a grown-up can watch along.
• Saving your spot is optional and only needs an email, which is never stored. It's turned into a scrambled code before anything is saved.