The mobile addon is located at https://addons.mozilla.org/en-us/firefox/addon/video-downloadhelper/

Hello henry_wong,

I don´t know what kind of download helper you want. > https://addons.mozilla.org/de/firefox/search/?q=download+helper&appver=25.0&platform=windows < Here is a list of all download helper who are avaible.

Guys the poster stated Firefox for Android as there is no Download helper extension in the Android section of a.m.o and the first posted link is for desktop Firefox.

https://addons.mozilla.org/en-us/android/search/?q=Download+Helper&appver=&platform=

titoxproxy, it would be best to use en-us links instead of German ones on this en-US forum.

Yeah I saw the category, but didn't know that it was not a mobile version.