I made the button float on the left side instead of the right because I already have a customer service button that floats on the right. It works fine on desktop and tablet. I will monitor user feedback to see if it interferes with the natural scrolling when using a mobile device.
It's been fun delving into the coding side of things after specializing in UI / UX design for so long. The start date for The Iron Yard is approaching at lightning speed. I'm excited. Can't wait to get the skills to truly "build something from nothing!" Computer programming is awesome!
PS. You can see how the back to the top button works by visiting my homepage at http://www.StephenWicks.com Scroll down the page a little and it will appear on the left side of the page. Cheers!