I am a YouTube lover and download all the video which I like. Which is easily possible with tubemate.
Tubemate is not available on play store but I recommend this app if somebody want to download video on their smartphone.
If you tap on menu on left top then you find there are so many different site are available to download videos. And here tubemate also shows what you previously search.
Very useful and easy to use if you play any video then tubemate pop a download option with all quality standard.
I personally love this app their is no point to hate is app