Buy TimeStory for Mac on the Mac App Store, with a one-time, up-front purchase for $49.99. (US prices shown; non-US prices vary.)
Download TimeStory-Trial-3.8.1.zip. If your Web browser didn't automatically unpack the zip file, open it in Finder to do so. Then run the TimeStory Trial app to get started! This trial has all app features and is fully compatible with the full app, it just has a time limit.
Get TimeStory iPad Edition on the App Store. If you just want to use it to open, view, or export documents, it's free to use. (It makes a great companion app to the Mac app, for presentations or on-the-go viewing.)
Creation and editing of timelines is unlocked via in-app purchase. Access this via Settings, or by tapping on a document creation or editing action within the free version. Choose either a one-time purchase for $39.99 or an annual subscription for $14.99/year. (US prices shown; non-US prices vary.)
Within the same in-app purchases screen, you can also choose to start a two-week free trial. This unlocks the full set of authoring tools; when it expires, if you don't purchase anything, the app reverts to the free read-only mode.
