Update: I am aware of the issue with Swipe Launcher launching when clicking on the Google Now Widget. it's a bug with Google Search and I have reported it to Google. It would help if you would do the same via the feedback tool in Google Now. Thanks!
Use Swipe Launcher as a supplement to your existing Launcher. Swipe Launcher replaces the up swipe from home gesture on Android 4.1 JellyBean and lets you customize which app launches with that gesture.
Extend Android and add multiple applications to your swipe up action. Easily access multiple applications including Google Now/Search.
Limited to 2 applications in addition to Google Search but upgradeable to unlimited with an easy in-app purchase.
The in-app upgrade also allows you to change the swipe gesture to launch a specific app.