I am a big fan of Nova Launcher and have been using it for quite some time. I am also a fan of Google Now which is very useful for getting the information that you care about at the right time. Unfortunately ( till now ), the only option to get the Google Now was to either open the Google app or configure a Swipe gesture on the Nova Gestures section. But that was missing the accessibility of Google Now launcher which had the option to access it by swiping to the left.
Now, Nova has introduced an option to have the Google Now configured on left swipe. But due to some restrictions on the usage of Google Now from Google, we need to have an apk from creators of Nova side loaded into the Android device ( no root required ).