Google Now might be fun and even useful for a few things, particularly those that use the Internet, but controlling your device completely by voice isn't exactly one of them. That somewhat changes when you install Commandr, which will let you use Google Now to toggle a few switches, at the price of three extra words: Note to self.
Google Now doesn't really have any provisions for injecting third party apps, even something like Tasker. From a security and stability standpoint, Google might not choose to do so and instead implement the functionality we see here right within Google Now, with very little options for customization or configuration. To circumvent this limitation, Commandr practically hijacks Google Now's note taking voice prompt by setting the app as the default Note app for the trigger. Whatever you say to Google Now after "note to self" gets piped to Commandr, which is then interpreted as a command.
So by saying "Ok, Google. Note to self turn off WiFi", you can effectively turn off, or on, your WiFi without having to touch your phone. Presuming, of course, it's in a state where Google Now can be triggered by voice. Sure, Google Now actually does have a turn on/off voice trigger, but that will only open up the WiFi settings and you'll still have to tap something to take action. Other commands including toggling the flashlight (presuming you have an LED flash), toggling Bluetooth, and controlling the media player. In case you're wondering what to do if you want a real note to be made, you'll have to say "Ok Google, Note to self note" and then your note's contents. Important note when setting up Commandr for the first time: you will reach a part when it asks you for the command to pause the media player. It is sort of a test whether you're paying attention and you should just enter "note to self pause music". It's quite confusing and undocumented and the developer plans on making that clearer in an update.
Admittedly, it might be a tad more work, at least vocally, for things you can do with a single tap using widgets and whatnot, but Commandr is quite useful for those times when you can't. Not to mention that it's a bit fun, too. The set of commands right now are quite limited but the developer already has plans to add more and even has a built-in voting system for popular requests. And then there's also Tasker integration, which opens up the app to a whole new world of possibilities, limited only by your device and whether it is rooted or not.