Up until recently I wasn't able to appreciate the full potential of a Firefox OS phone. I only looked at it as a consumer product, a cheap way for people in developing countries to get access to the internet. I had never considered its potential as a tool for hackers and developers.

So here is my use case: I own 2 prepaid SIMs for which I regularly run over my internet quota. Vodafone has a promotion where it offers you 2Mb for every call you give or receive, that is over one minute long. The problem is, I don't really talk for more than 20 minutes each month. So, as the bright engineer that I am, I've come up with a plan. Since I have unlimited calls between my two prepaid SIMs, why not have them call each other, and farm some megabytes.

Here is where Firefox OS comes in. It's insanely easy for me to script together some code that would call a number, wait for 60 seconds, end the call and call again.

function start() {
    navigator.mozTelephony.dial('07XXXXXXXX'); // Call the phone number
    setTimeout(stop, 63*1000); // Stop the call in 63 seconds
}

function stop() {
    navigator.mozTelephony.calls[0].hangUp(); // Hang up
    setTimeout(start, 3*1000); // Call back again in another 3 seconds
}

start();

I just opened the App Manager, and pasted the code into the Usage app console. Then I left it running for about one night, and got around 1.5 Gb of traffic. (The max I can get is 2.5 Gb) Pretty nice, right? One of the problems in this setup, is that I needed to download an app on my Android phone, to answer incoming calls automatically. I went with AutoAnswer, but wasn't really happy with the permission settings the app required. This is another way Firefox OS kicks Android's app. It has a way better permissions system, where each app asks for each permission, and can still function if you don't allow it.

So there it is. With less than 10 lines of code, I was able to make use of the phone's capabilities in a very cool way. That was way easier and much more fun than anything I could do with my Raspberry Pi. Soon, with the launch of a device that costs around 25$, it will be even cheaper than a RPi. And I can only imagine what I could do with the the available camera and wireless capabilities.