Yeah that's where it becomes a bit difficult, I find. Although the kit focuses on Chrome Extensions, you can actually convert the result to a Firefox extension

Yeah that's where it becomes a bit difficult, I find. Although the kit focuses on Chrome Extensions, you can actually convert the result to a Firefox extension with some minor tweaks (and I'm hoping to add some tools to further simplify this). I had a similar experience with Firefox and I think for some, it's hard to justify that extra effort (from development all the way to publishing) given the current market share of Chrome in comparison.