Get GPS based Location in Iphone

Okay well i have to make a game which used user's current location based on GPS and then find all other users about a 10 meter range.I thing to remember there is no need for WIFI because GPS works fine when WIFI is not activated.i confirm by checking the maps app on Android and IPhone.

For Android i found a solution and write a plugin basically a jar file and then import in Android folder and just use it

http://www.mat-d.com/site/unity-gps-plugin-development-tutorial-building-a-android-plugin-for-unity-with-eclipse-and-ant/

But Now i want to create the same app for IPhone i know i have to make some kind of plugin to get GPS but i can't find any good article or some thing which helps. i also see Writing Plugins video by MeikGeig in which he teach how to make managed and unmanaged plugins but for my case it's not helping.

How to Write a plugin that use GPS Coordinate and then use in Unity3d ??

Any help Appreiated thank in advance :)