Definitely need something like M-PESA in the USA. In Kenya you get an M-PESA account with your SIM card, no bank account required. You can use M-PESA to pay for anything, even to buy one banana from a little old lady selling produce out of a shack. Groceries at any supermarket, gas at any gas station, any bar or restaurant, etc. You can go into any shop and exchange shillings for M-PESA and vice-versa. Also converting USD to send to M-PESA from a US bank is inexpensive, only a few dollars in fees, or no fees depending on which money transmittal service.
It's maybe similar to cash app, venmo, paypal etc but i think M-PESA is more convenient. Anyone with a kenya phone has it and uses it.