Watching movies at different speeds is known mainly from YouTube, but as it turns out, other producers see the potential in this function. It allows you to watch recordings faster, which in the case of documentary or nature films allows you to watch video faster, but also watching recordings in slow motion gives you the opportunity to analyze movies frame by frame. The video speed change is tested by Netflix, which has made this feature available in a beta version to some users using the official Netflix's app on Android.

Netflix wants to provide customers with the option of watching movies at five different speeds: standard (1x), 0.5x, 0.75x, 1.25x and 1.5x. So far, there have been three reports on the Internet indicating that the feature is tested only on Android, but if the tests are successful Netflix will certainly add this option also for customers using iOS.

source