Dear friends it’s very easy to download Youtube video through mobile. i will given you easy steps please follow these steps to download youtube video download.
Download Youtube video from mobile
1 Step – First go to the videos you want to download and click on share button like snapshot 
2 Step – Copy youtube video link like given in snapshot below

3 Step – Open any browser like chrome like given in snapshot below
4 Step – Open FBVIDGO.COM website and click on red button “Youtube Video Donloader” like given in snapshot below

5 Step – Afterward you have to appear new window paste here youtube video link (long press on text box you see paste option appear click the paste button) – After this click on Start Download button like given in snapshot below

6 Step – Afterward you have to appear many download link click on button to download (long press on direct or proxy button and download link) like given in snapshot below

Here you can download many sizes video