I'd enjoy a voice control which isn't tied to a device, but more like an Alexa+Siri+Google Now "in a stick with a button to initiate listening and a hardware sw

I'd enjoy a voice control which isn't tied to a device, but more like an Alexa+Siri+Google Now "in a stick with a button to initiate listening and a hardware switch to physically turn the mic off". One that understands "Google, set a timer for 5 minutes" as well as "Siri, remind me to call X tomorrow" and "Alexa, start Y on the TV in the living room"