One of crypto's big drawbacks is: what happens when the internet goes down? Does the economy just come to a screeching halt when it happens? Bitchat is a Bluetooth mesh network that helps solve this problem. If the net goes down, people can still buy and sell crypto as usual, until the day the internet comes back up. We need more apps similar to this. While it has been funded by Jack Dorsey, the former CEO of Twitter, it is open source on Github and in the public domain, and so far runs on Android. iOS, and macOS.