User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0 Build ID: 20171102181127 Steps to reproduce: One of native messaging's use case is password managers, and they're just as important on Android. I propose here to implement support for it. (Chrome doesn't support addons on mobile, so it doesn't matter anyway.) Some ideas in detail: - Two ideas for authorization: * writing to shared storage * launching a Firefox activity from 3rd-party app and prompt the user - Messaging itself should use a bound service, and "piping" should occur through binder. To make it similar to the desktop API, it should be kept to be a simple text read-write interface.