The Continue Watching features allows you to stop a video, do something else and then come back later and resume the video on the same device or another.

This feature is available across all devices.

All the films you have not competed watching will appear in a band or carousel titled: 'Continue Watching'.

Just click on the film you wish to continue watching and then (1) click on the Play button to resume watching -- the film will pick up from where you last left off. 

You also have the option to restart the video from the beginning. You can do this  by clicking Reset Playback (2)