Ключевые слова: app, application, apps, bar code, bill, business, buy, cellphone, check, code, concept, cost, customer, debit, device, digital, electronic, expenses, gadget, hand, holding, identification, internet, list, mobile, paper, pay, paying, payment, person, phone, pile, professional, purchase, reader, scan, scanner, scanning, screen, sell, shop, smart, smartphone, spending, technology, telephone, touch, touchscreen, transaction, using,