For about a couple of weeks, Nightly has been unresponsive to touch input on my phone. On further investigation, I find that it works normally when I turn off Lux (http://www.vitocassisi.com/), a brightness control app that also applies a warm filter after sunset. I expect that the behavior I'm seeing is from setting filterTouchesWhenObscured for the entire Firefox UI, to avoid security issues from clickjacking. Please add a configuration option for this setting so I can turn it off and continue using Nightly and Lux together. You might also want to pop up some sort of warning for users like me wondering why Firefox seems frozen; until today I assumed it was a bug that would be fixed soon.
This was disabled a long time ago.