User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2516.0 Safari/537.36 Firefox for Android Steps to reproduce: I tried install WebExtension in Android. But not working. Actual results: When will support WebExtension for Android?!

This is a very good question. Your best hope for making an android add-on today maybe by using the Add-on SDK, a restartless add-on is another option but I think less likely to be supported in the future, based on what I read at https://blog.mozilla.org/addons/2015/08/21/the-future-of-developing-firefox-add-ons/