I'm on an Android where the Facebook program came default. I've never logged into the site using my device, and I never will. But thanks to the way Alcatel, TracFone, and Facebook have it worked out, the best thing I can do is "Force Stop" and "Disable" the program rather than uninstall it and remove it from my device. It definitely makes me worried about logging into any website - even in "Incognito Mode", because it says to me that someone wants to know what I'm doing whether I like that or not.