• Android version: 6.0.1
• Phone model: SM-G900FD (klteduosxx)
• Briar version: 0.16.9 (07853488)
• User feedback: "After adding the phones as contacts to each other, I can send messages from one to the other, but only via Bluetooth. No messages are exchanged per WLAN or mobile Internet connection."

The log shows a successful outgoing Bluetooth connection and a message being offered. I've asked for more information.