It's small payments what are are mostly done in cash, like the $0.20 bus fare, $1.25 lunch, $0.50 soda or $0.25 tortillas. There is no widespread electronic alternative for those payments yet here.

Free mobile banking accounts have been available for a while in El Salvador, and can be opened with a selfie and a photo of your national ID. They are only avaialble for those 18+ and older though.