Following on from yesterdays post, Soft Schools also have an online timeline generator which you can access here. This would be more suited to the younger years as it is definitely a lot easier than tiki-toki, but it definitely does not have the fancy looking timeline that you can create with tiki-toki. The timeline allows you to add text and dates.
One of the disadvantages with this site is the children are unable to save their work, so all work would need to be completed in the session, it does allow you to print out your completed timeline at the end however.