I have Briar, but never had anyone to use it with. As an emergency text messaging tool, I guess it can be used, but not for any media transfer. The picture quality is abysmal. I also tried using it to sync some notes across devices, looking for a good use case of it all, but there was also some issue there. I believe once you created a "forum" you can no longer delete them. The desktop app is very slow. Sometimes had to wait for 10-20s for it to do something. I guess it is really just an emergency/offline text message tool.
A good use of briar is having it on your phone already so that during a natural disaster you can connect with others that already have it at community relief spots. Keep it just in case and it will come in clutch when you need it most!
Briar comes with ways of sharing it offline, so enough for one person to have it.
Most likely how they got it in Iran, as I doubt that critical mass of people had it installed in advance. Most likely doesn't work on iPhones though - no sideloading.
I looked into the iOS issue once, and in the EU at least, it should be possible to add a minimal implementation of the store API to an app, so other iPhones could download the app from an iPhone hosting it.
After discovering the amount of pain involved with that API, I quickly discarded the idea though
Source? I guess you're thinking of long tap → Airdrop, but that essentially shares a link to the Appstore via Airdrop. You're not transfering the app itself.
