The INSS Invoicing Facultative mobile application is a tool aimed at insured persons of the optional regime of the Nicaraguan Institute of Social Security (INSS) that facilitates inquiries of invoices issued and pending payment, reviewing the payment history and carrying out different procedures; such as requesting the sending of invoices exclusively by email and verifying your IPSS of affiliation, all this from a mobile application. Through this App the Nicaraguan Institute of Social Security makes available to the insured of the physician a modern, novel and free option to have timely access to Billing, data and procedures before Social Security using new technological trends.