The battery in my LunaSix was installed in 1998. My Weston doesn't have a battery/cell, just a photovoltaic cell which was factory installed. In the mid 1950s.
But by all means, go out and get an i-thingy. Don't go far from an outlet, though.
As previously mentioned, buying an iPhone for the purpose of installing a light meter is asinine. But if you're going to have a smartphone that is capable of also being a pretty good light meter, why not add the capability? Or are you just so bitter that you have to piss on everything that isn't to your taste?