You can invite someone to Signal using the "Invite Friends" menu in the app, which will send a text message or email.

You can forward a message on Signal, the secure-messaging app, just like you can on iMessage or Facebook Messenger.

Instead, you need to open and register Signal on the new phone and select an iOS transfer. Then you use a QR code to connect the old and new iPhones and a transfer will begin. Be warned — that ...

One exception to the industry-wide lethargy is the engineering team that designs the Signal Protocol, the open source engine ...