SkyTube Extra APK is an alternative, free, open-source YouTube application for Android. It allows you to use YouTube comfortably without the need for Google/YouTube account and hence this app only offers read-only access to YouTube.
access to videos from Featured and Most Popular lists;
watching YouTube channels;
playing videos from YouTube;
view comments on the video;
search for videos, music and channels;
channel subscription and unobtrusive notifications.