Youtube Detox - Distraction-free Youtube search
F-Droid - F-Droid is an interesting alternative for Android users who want to try something different and not have to use the Goole Play store all the time.
YouTube Trending - Making it easier to find viral videos
APK Pure - Download apk for Android with APKPure APK downloader. NoAds, Faster apk downloads and apk file update speed. Best of all, it's free
YouTube Messenger - YouTube in-app video sharing and messaging
APKMirror - Android Market and APK Downloads