I use timelines to track events, used in my writing, but I see ways to use them even more. When I ran into a backstory, I needed to expound on, I used a timeline. Timelines can act as outline and storyboards. Most event in a novel take place in chronological order, but a time line can flowchart back to a backstory event.
The one site that may have been the most use to me is–myHistro.I move in time and place, in my novel, and myhistro seems capable of handling my story. The site even advertises the story creation ability.The map–timeline, in the left, comes from myHistro.