Update unavailable?

I will preface this with the fact that it's very possible I'm being an idiot and have missed something.

That said: I can't seem to download the latest version of the app. If I go into TestFlight, Imzy is listed as "unavailable". Has it expired? I can still get into the app just fine.

I'm on an iPhone 6 running iOS 10.0.2 if that's any help.