Last time I showed you the Flame device
which is our reference device for

developers

and people who want to get to know what a mid-tier device on Firefox OS would look

like.

Once you have your Flame set up it comes like this. By the time the video is out, there

might be a new one so keep up to date,
it's really easy to upgrade your

operating system.

To turn this phone into a proper developer
phone you just go into settings

and you go into the internet settings

of the phone itself: "device information".
Once you're there you click on "more

information"

and then you turn on the developer menu.
When you now go back to the main settings

you will get a developer menu that would
be confusing for normal end users

but is a real real interesting point for
you as a developer.

You have for example the layer borders, 
you have tile borders, a hardware

composer, the tiling, the over scrolling:

everything that happens in the interface
itself to the video card

to the memory can now be inspected by
you and that is much much better than

trying to do it over USB and seeing it
in the ADB

log but you can do that as well if you
wanted to. A very interesting new section

that we have in Firefox OS now is the
"developer HUD".

Once you turn that on here and you see
it it overlays information onto the

screen for you.

You show the system HUD and all of a
sudden you see how much memory is being

used by the system right now

and how much memory is being used by the app that you're currently debugging.

As everything in Firefox OS is an
application including the Settings screen

you can actually debug that setting
screen while you're using it.

You can also turn on the frames per
second which shows you up there how many

frames per second are being used,

the time to load: how long it took to
actually load the application that you have

right now,

reflows, yank and all those different
settings that you need as a developer.

You see the memory consumption of the
app itself and you can cut it down to

like how many JS objects, JS strings and so on have been set for you.

That allows you on the device to see how
your app is doing

and for app developers that has been
always a pain so we set up this HUD for

you.

Turn it on, test your application, tweak it 
until it's fast and then bring it to the

marketplace

and other Firefox OS users out there
will be happy.