I am working on an application like 'Viber' for iPhone ( http://www.viber.com/ ).
I need to use the user phone number as ID in my database.
When the user launch the application, I need to determine which contacts use the same application. I can get contacts phone number with ios API.
But this scenario is problematic when considering country calling codes ( http://en.wikipedia.org/wiki/List_of_country_calling_codes ) :
When "registering", the USER A type his phone number without country calling code. The USER A is in the contact list of USER B, but without the country calling code.
For instance, in France : +33 x xx xx xx xx is refering to the same phone that 0x xx xx xx xx
Is there a simple way to resolve this problem ?