I had the same issue with the app trying to install over data network instead of over wifi. Every time that I did a force stop on the download, it would just start up again in a few seconds. I eventually uninstalled FB and did a force stop and all went quiet. Supposedly it was only sent to those who had the mobile FB installed, only sent over wifi (not true), and only to those who would accept from "unknown" sources (read: everybody who has installed amazon app store and not gone back to uncheck that box.) If they can't update it through the Play store, they can keep it. I found this to be way over the top.