Microsoft is introducing a new Timeline feature for Windows 10 today. It's a feature that is designed to allow Windows 10 users to switch between multiple devices, including Android and iOS phones. Microsoft has built a Timeline view straight into the existing Task View feature for Windows 10 that includes an overview of currently running apps across Windows 10 machines and iOS and Android devices.
Timeline will let you effectively pick up where you left off if you're switching between Windows 10 devices. Thanks to Cortana integration, this will even extend to some Microsoft apps on iOS and Android. It's really designed to be a quick way to move from one machine to another, much like Apple's continuity feature in iOS and macOS.