So we have that somewhat useless Bixby button on Galaxy phones. Now I am not against Bixby, quite the opposite. But I prefer to summon her via voice and use the button for something I commonly need to happen fast - turn on the flashlight.
Recently Google started rolling out this new feature to Windows users and apparently it is possible on Android as well. It has been in the Chrome for Android Beta for quite some time. You can follow this tutorial to guide you through the process.