Let the cat and mouse games begin... I think? Now I am pretty confused about what is going on. Verizon had seemingly blocked FoxFi from working on their network. I tested it on several devices last night to find that, just as reported, it was no longer working on the Verizon network. Now I'm left wondering if there was just some sort of issue on FoxFi's side keeping the app from functioning. Verizon nor FoxFi ever made any sort of statement on the matter. Verizon never sent out an update blocking it, and I never received an update from FoxFi to make the app work again.
One can only speculate at this point. A few years back the FCC ruled that Verizon couldn't block these types of apps from being downloaded. This was in response to Verizon blocking tethering apps from the Play Store. If Verizon blocked the app from working maybe they unblocked it to keep from being fined. Blocking it totally would mean that both unlimited and tiered data users could not use it.
Maybe FoxFi had a fix waiting on the moment that Verizon finally blocked current methods and simply deployed the fix on their side. The most likely scenario is that FoxFi experienced some down time and just never let us know that this is what was going on. At any rate you can once again enjoy FoxFi on your non rooted device to wirelessly tether for free!