If you use Clef 2-factor auth. sign-in on your WordPress website(s), the app/plugin will stop working after 3 months from now. I have never used it myself, I saw that it had too many issues from the beginning, but many people do (in the millions actually). WordFence does have cell-phone sign-in, but only with their premium version. (which is expensive) …WordFence premium is $99 a year for a single license. It goes down significantly if you buy more licenses though. I would buy it unless I could get it for around $30, which requires signing up 25 licenses. If you are interested, send me your info, and if I get enough people together to get cheaper licenses, we could get them as a group. The final shutdown date for Clef is June 6, 2017. If you want to read their post, it’s here: https://blog.getclef.com/discontinuing-support-for-clef-6c89febef5f3#.nxyejqdl9