Smartphones are so ubiquitous in today’s society, it’s hard to imagine life without them. But when the dead start walking the earth, and civilization as we know it goes to hell in a hand basket, the luxury that comes with these devices will no longer be available. Or will it?

Antony Leather, contributor at Forbes addresses this question in his article “Would Smartphones Be Useful In A Zombie Apocalypse?”

And his answer is absolutely “YES!” At least for the first little while, which is fortunate, because it is most likely when the largest amount of excrement will be hitting the fan. It turns out your smartphone can be an electronic Swiss-Army knife for the apocalypse, and we’re going to tell you why.

First, the electricity issued must be addressed. With the addition of a power generator of some sort, be it a diesel powered generator or solar panels, the creation of the electricity that your mobile phone craves is entirely possible. At least until the diesel and/or sun runs out.

So while your smartphone is functioning, what would it be good for?

Let’s make some assumptions first. Most of the machinery of society would likely continue to work for a short period of time after the initial “disaster”, depending of course on how widespread the “disaster” is. But soon cell towers, routers etc. would stop working without a supporting power grid, and with it the internet and telephone.

Most cellphones have a host of built-in functions, outside of standard communication, that will continue to be useful as long as they have power (see generators and panels above). For example, a phone can find its location using GPS (Global Positioning System) by interacting directly with satellites in orbit around the earth. The documentary Aftermath: Population Zero (The World After Humans) predicts that satellites would stay in orbit for approximately 30 years before plummeting to Earth. They would however, begin slowly spiraling inward for those 30 years, and it is uncertain at which point they would no longer be useful.

The compass in most phones use a magnetometer chip, and would work without access to GPS. If you had a sextant (and let’s face it, who doesn’t), you could use the very-accurate clock in your phone to work out your longitude and latitude. The calculator would be useful for all kinds of calculations needed for survival, like rationing and fuel consumption.

Antony Leather also suggests that you load your phone up now with apps that might be useful during the apocalypse. Informational apps like Wild Edibles, First Aid, Cooking, as well as alarms, stopwatches, flashlights and sound detectors will all be useful even when the grid is down.

And of course, as a very last resort, you could throw the dead phone at a zombie. Mind you, the older brick-style phones would be more useful for that purpose.