Use APKPure App
Get Small Tube old version APK for Android
작은 응용 프로그램으로 유튜브를 재생합니다.
Play YouTube with a small screen, you can other work.
A version that can be used on terminals other than XPERIA is here! ↓
Small Tube for All Device
[ SmApEx4SoPr ] Small Apps extension for Sony products