1
Open it and drag across
Double-click the .dmg and drag Chatter into Applications. It's notarised by Apple,
so there's no warning to click through.
2
Let it hear you
On first launch macOS asks for the microphone. Talking is the whole app, so this one isn't optional — everything else is a switch you control.
3
Sign in with Google
Your browser opens, you pick an account, and that's the whole sign-up. Your name and picture come from Google; there's no password to invent.
◆ Then say this
“Chatter, ask Matt whether the presentation is ready.”
If Matt is on Chatter, his assistant will tell him — and yours will tell you the moment he answers. If he isn't, Chatter will say so plainly rather than pretending.