Install the desktop app and a small bubble floats on top of every app. Click it to talk, type, or run actions — then it tucks away until you need it.
Open the installer. Windows may show a SmartScreen prompt the first time — click 'More info → Run anyway'.
It installs in a few seconds and a floating bubble appears. From now on Jack autostarts with Windows.
Click the bubble, hit Sign In, and you're in. Talk to Jack hands-free or open the full app anytime.