I have found that Hello KlicK from the Play Store works the best for my needs so far.
I am going to keep doing some research because I would really like the button to enable/disable Expanded Desktop. But, for now, I have single click set to Open App: Nova Launcher, and that allows me to skip the lockscreen and go right to my home screen. Double Click to Open App: Camera, and triple click to Open App: Hello KlicK. A long press naturally opens Google Voice Search even without Hello KlicK installed, so I left that option alone.
I was just wondering if anyone else had any experience with one of these, and I would also be glad to answer anybody's questions about mine.