Square

 Square  is a company that offers financial services, including software and hardware to collect payments with mobile devices.

Square Up
Square Up is a service for taking payments by credit card that works with a special "Square" device that plugs into an iOS device's headphone jack.

Other hardware options are available also.

Square Cash
Square Cash is a different service for exchanging money using debit or credit card payments. Creates a simple-looking cash.me/$username URL to share for people to pay you. An amount can be pre-selected by adding it to the URL, e.g. https://cash.me/$username/10.

You can also send a request to another Square Cash user, email address, or phone number:



Articles

 * https://medium.com/look-what-i-made/294e9d2eb58b