On OS X, Echoes is an “invisible” application that places an icon in your menu bar. To use Echoes just choose an Announce command from its menu (or press a keyboard shortcut), speak your announcement, and press return. It's fast and easy. Announcements can be sent to individuals, groups, or everyone on your network that is also running Echoes. From the menu you can make announcements, configure preferences, and get other information about the software.
On iOS, Echoes is an app that lets you send and receive announcements to other Echoes users (OS X and/or iOS) on your local network. To send simply select the recipient(s) from the table, speak your announcement, and tap Send.
How much is it?
Echoes for Mac is available for a limited time for $9.99 (USD) Echoes for iOS is available for $4.99 (USD)