Google made their YouTube Go app available in beta back in February and now the app is out of beta. The new YouTube app is a lightweight version of the standard app. The new YouTube Go is designed to let you save and watch videos offline.
The app is designed to use less data than the standard YouTube app. The app is only available in some countries at the moment, it is available in Indonesia and India at the moment.
The design of the app is similar to the current YouTube app, although it does have some different features. You can control the quality of video and you can also send clips to your friends over Bluetooth.
It is not clear as yet on whether Google plans to roll out their YouTube Go app to more countries, as yet there are no details on when it may land in the US or the UK.