Found one downside with the Fox apps vs the Hisense one last year: No watching games on demand. You can only watch what is airing now (so the only way to watch a game after it has happened is if they replay it on FS1 or wherever). Also apparently they now have a "Fox Sports" app, that's different than the "Fox Sports Go" app that I used to use. And the "Fox Sports Go" app is only for my local/regional Fox Sports Networks now, whereas the "Fox Sports" app is for the national Fox Sports channels (but not the regional channels).
Also if a match is on FOX soccer plus and your TV package does not include FOX soccer plus then when/if it replays on FS1 or FS2 you can watch it as it replays BUT you cannot watch the archive even after the replay airs. Of course if you have a streaming service like Sling and have the DVR you can DVR the replay and watch the DVRed replay at your leisure. There is not much rhyme to the reason of the FOX rules. It is inexplicable like most of anything in the FOX universe.
Yeah I've been having issues with Fox Sports apps. I often shuffle through Fox Sports, Fox Sports Go, and just regular Fox.com. because I don't know what the differences are and for some reason I have to sign on to my DirecTV account a zillion times for the streaming to work even live. I made it to watch the 4AM Italy-Australia game(West coast first world problems) but I was tired by the time the England-Scotland match was on so I thought I could take a nap and watch it on replay. It took a lot of refreshing, 10 sign-in activations, etc. just for Fox site to allow me to watch the replay. I would constantly get a message saying that my "subscription" doesn't allow me access to this content. I don't remember Fox being so annoying four years ago during the last WWC when I rewatched the matches on repeat. I might have to just go old school and DVR the matches on my television.
I guess it has a lot to do with the provider. I use Sling and I signed in on the Fox apps on three different devices about six weeks ago and I have not had to sign since. Of course I am a suspenders and belt kind of person so I DVR matches on Sling and use the Fox apps to watch live. I prefer the Fox apps for live because Sling is generally about 45-50 seconds behind while the Fox apps are usually less that 15. BTW: Both Sling and Fox are only about 5 seconds behind when the apps are run on a Windows computer but the convenience of the interface on my Roku, Fire TV and Shield TV pretty much offsets that advantage. For the first few days of the WWC I have had no problems. One more thing: The fact that fast forward pause and rewind are disabled on the actual Fox app and when watching Fox live from the guide is a disadvantage that often forces/encourages me to use Sling's DVR and watch the recorded content as it is recording. That produces an additional delay of 10-15 seconds but it is worth it unless I am chatting with someone that is watching live.