I've had the privilege of briefly trying out Timeline, and as of current internal builds it's simply a glorified recent apps screen that houses apps that were open in the past as well as apps that were open across devices. (windowscentral.com)
The current iteration of Android's standard recent apps screen - officially called the Recents or Overview screen - that lets you switch bet... (sammobile.com)
Some of the elements of Android 5.0 Lollipop make its way over to the Zenfone Zoom, including the card style Recent Apps screen and a revamped notification drop down and quick settings menu. (androidauthority.com)