Your cell phone can make a pretty good backup with any number of cheap apps. While it can't give you airspeed, it can give you GPS ground speed and that is close enough to get on the ground. Plenty of apps to show speed, altitude, even efis type displays.
The other thing you can do is buy a Stratus and it will give you an AHRS system that can play on your iPad, iPhone, or Android device and have ADS-B in.
I also agree that a competent pilot should be able to get one on the ground without any flight instruments whatsoever. I have practiced this on all of the airplanes I have owned. The Kitfox is on the low end of that spectrum and the Twin Comanche was the highest performing I have owned. I do it with another CFI who can monitor things while I fly circuits without being able to see the ASI or altimeter.