Mozilla has an app that allows you to essentially run Firefox OS 2.5 on your android device.
So, after downloading the APK, which you can only get from Mozilla’s website, you’ll install the APK. Make sure you have allow unknown sources for app installs turned on. This is under settings/security for most Android versions.
Once you tap on the icon you’ll be surprised to see that it’s not really an app. It’s a launcher. Which is a really great idea! It takes a moment to load the first time. You’ll get a bland welcome page and a continue button at the bottom.
The first thing I noticed right away was the top notification panel looks like Firefox OS. It’s nice enough and has a nice transparency to it. One thing about the app/launcher is that touch the top notification panel you’ll notice that you can trigger the Android notification panel by kicking you out of immersive mode. This really isn’t the fault of the developer preview. In fact it gives me the opportunity to publicly say to Google and Devs that I think immersive is just that, immersive full screen. It should be two swipes down to get the notification panel or something while in immersive mode. It ruins a lot of apps in my opinion; especially home launchers.
Watch the screen recording I made to see me flip through some of Firefox OS 2.5. The last time I used Firefox OS was on my Nexus 5. This was more than a year ago. One thing that’s much different (this might be slightly something to do with my current phone being a Galaxy S6) is that the app icons are enormous. This may very well be a personal preference. I’m one of those guys who lowers the DPI on every.single.phone I have.
It seems Firefox OS has come a ways since I have seen it last. The streching icons effect is a little childish in my opinion, but I know a lot of people will think it’s fun. Really, that’s about the only complaints I have. I haven’t looked at their developer documents yet. But, I will say, being a web developer I’m pretty excited that I can do my normal thing to make apps. Not that developing android apps is really all that much different, but, it’s nice to know that it won’t be much different at all.
Source: FireFox OS 2.5