Watching videos through the YouTube Android app is a decent experience as is but Google is always looking at ways to improve anything they can. While YouTube for the web looks to be gearing up for a material design implementation, the Android app is gaining an autoplay feature soon as the function seems to be appearing for some users. With autoplay being introduced into the Android app users will be able to bring up videos, begin watching, and simply let things continue playing as the next video in line would start to play immediately following the completion of the first one.
There's no detail just yet on if this is a small batch roll out to a handful of users, so there's no telling how long it may take for everyone to have the feature enabled. The good news for those who don't care for autoplay is that the functionality will be optional as it appears in the form of a toggle switch right under the video subscriber number details, so users can simply tap that toggle and disable the autoplay before watching anything. Autoplay in the YouTube Android app will work in the same way it does on the web, with videos up next in the list playing automatically after one finishes, making it feel like a library of videos have been queued up.
As with anything that Google adds into their app there is always the possibility that they could take the autoplay feature away at some point in the future after rolling it out to users, but that likely wouldn't be too soon after introducing it. The app shows up for us here on at least one device and the app hasn't been updated too recently, so the feature is likely server side. If autoplay is something you've been waiting on with the Android app you can always try checking to see if it's already available to you and if not then it should just be a short wait with the chance that it will either pop up later on today or sometime throughout the rest of the week.