Does plugin work outside the US?

Yes. However, you may need to modify the account object according to etapestry rules per country.

Here is an example of how to accommodate an address in the UK/Great Britain:

add_filter('eTapMapping_donor','my_modify_donor_fields',10,3); // for Mapping plugin
add_filter('eTapPayment_donor','my_modify_donor_fields',10,3); // for Payment plugin
/**
* Change state to county
* @param array $donor
* @param array $data
* @param array $feed
* @return array modified $donor
*/
function my_modify_donor_fields($donor,$data,$feed){

// change state to county

if (!empty($donor['state']) && $donor['country'] == 'GB'){ // your country code 
$donor["county"] = $donor['state'] ;
unset($donor['state']);
}

return $donor;
}

 

Please visit

https://app.etapestry.com/hosted/files/api3/objects/Account.html

to see all country adaptations. Address field rules are at the bottom of the page.