The following error message occurs during export to Salesforce in Business Card Reader for iOS:
Failed to export to Salesforce Lead
Contact you trying to export already exist. Please change the required fields.
The error message is related to the Salesforce settings not to the BCR for iOS application. The creation of duplicates is not allowed in Salesforce.
To fix the issue, please check the instructions in the article of the Salesforce Help: Disable Account Duplicate Rule.