Is there a possibility to send geolocation data to the piwik server from client side javascript or api (mobile). In our case, every request is transferred via a proxy server with the result, that ip address of all requests are the same. (If the user gave allowence to use the location data.)
You can call the UserCountry.getLocationFromIp API but you wil need to pass it the Visitor IP address. See http://developer.piwik.org/api-reference/reporting-api#UserCountryhttp://developer.piwik.org/api-reference/reporting-api#UserCountry