As I understand it, these kind of applications depend on being able to perform activities in the background, which is highly limited in iOS for battery efficiency reasons–and maybe for privacy.
Many years ago I was working on a project that shared connectivity details over wifi/bt, and iOS was troublesome also due to the application not being aware of the local bluetooth address.
Possibly similar issues impact other mesh networking applications on the platform.
I guess they can be pretty safe from radio interference there, at least :).
I doubt the connectivity issues need to exist, though, probably works just fine in some configurations. What I'm wondering though if they had a spare, and maybe a second spare, and space batteries, on the boat. Or possibly manual override (doesn't sound like it).
I think the device itself is fine, though it might be indicative of too aggressive cost cutting measures.
FireChat was a tool for revolution. Then it disappeared. (www.fromjason.xyz)
The only manned submersible that could reach the missing Titan is owned by Steam's Gabe Newell (wegotthiscovered.com)