Downloadable music files authenticated by non-fungible tokens (NFTs); downloadable multimedia files containing artwork, text, audio, and video authenticated by non-fungible tokens (NFTs); downloadable computer software and applications for mobile devices for facilitating and administering banking, payment by credit card, debit card, or virtual payment card, automatic teller machine services, stored value card services, electronic funds transfer services, electronic payment processing services, electronic processing and transmission of bill payment data, cash disbursement services, transaction authentication services, routing, authorization and settlement services, and fraud detection and control services in the metaverse and other virtual worlds; downloadable computer software and applications for mobile devices comprising a digital wallet that stores customer account information and permits consumers to access coupons, vouchers, voucher codes, discount codes, and rebates at retailers and to obtain loyalty or monetary rewards that can be credited to their accounts in the metaverse and other virtual worlds; downloadable computer e-commerce software to allow users to perform electronic business transactions in the metaverse and other virtual worlds