Devices

Onetouch Fire

Alcatel - Onetouch Fire
Peak

Geeksphone - Peak
Nexus 4

LG - Nexus 4
Nexus 5

LG - Nexus 5
Moto G

Motorola - Moto G
Xperia E3

Sony - Xperia E3
Xperia M2

Sony - Xperia M2
Xperia T2 Ultra

Sony - Xperia T2 Ultra
Xperia Z1

Sony - Xperia Z1
Xperia Z1 Compact

Sony - Xperia Z1 Compact
Xperia Z2

Sony - Xperia Z2
Xperia Z3

Sony - Xperia Z3
Xperia Z3 Compact

Sony - Xperia Z3 Compact
Flame

T2Mobile - Flame
Open

ZTE - Open
Open C

ZTE - Open C
Add-ons
Firefox OS 2.5 introduces support for add-ons, a feature that desktop users have known and loved since the beginning of Firefox. Add-ons on Firefox OS are even more powerful and can customize the whole phone experience.
Gaia Development
The focal point of Firefox OS is the user experience, and that experience is a collection of Web apps called Gaia. Gaia includes the core system app that implements the window manager and system UI.
Try B2G Droid
B2GDroid is an Android launcher that replaces the core Android homescreen experience with an alternate Firefox OS experience.