Want to run Mozilla’s Firefox OS on your smartphone, but don’t feel like buying a new (and entry-level) phone such as the ZTE Open C or Flame reference phone? No problem. If you’ve got a Google Nexus 5, you can just install abtekk’s build of Boot 2 Gecko to turn your Android phone into a Firefox device.
Boot 2 Gecko is the open source version of Firefox OS, and while it’s designed to support relatively inexpensive devices it has no trouble running on the Nexus 5 with its full HD display and Snapdragon 800 quad-core processor.
The unoffiical nightlies run smoothly, supports WiFi and cellular data, and allows you take snap photos with the camera. But there are still a few things that are broken: You can’t actually preview photos before taking them yet, and WPA-2 Enterprise security isn’t supported.
Before installing this ROM on your Nexus 5 make sure to backup your data using TWRP, ClockworkMod or another method — and make sure to copy the contents of your device’s storage to your PC for safe keeping, because installing B2G will erase your internal storage.