Downloadable computer software for processing electronic payments and for transferring funds to and from others; downloadable software to enable the transfer of financial instruments; downloadable mobile application software for processing electronic payments and for transferring funds to and from others; downloadable application programming interface (API) software; downloadable computer software for management of user identification; downloadable authentication software for controlling access to and communications with computers and computer networks; downloadable computer software using artificial intelligence (AI) for the finance and banking industry; downloadable computer software for issuing receipts regarding mobile payment transactions