Whisper is an iOS/macOS application that allows someone without voice---the whisperer---to participate in conversations. The whisperer types on their device, and as they type the letters appear instantly on the devices of all the other participants in the conversation---the listeners. The listeners then speak their responses directly to the whisperer.
When the whisperer and listeners are together in one place, their devices connect automatically via Bluetooth so conversations don't require any set-up. When the whisperer and listeners are in different locations, the whisperer first sends a link to the listeners, as well as getting them on the phone or in a video conference. The Whisper app makes it easy to send and receive these links.