Square, Inc. enables payment processing, and also offers financial and marketing services. The Company provides sellers various tools to start, run, manage and grow their businesses. It serves sellers of all sizes, ranging from a single vendor at a farmers' market to multinational businesses. It serves as a payment service provider, acting as the touch point for the seller to the rest of the payment chain. Square Register is a point of sale (POS) software application for iPhone operating software (iOS) and Android, and is available to sellers across the world. Square Reader for magnetic stripe cards plugs into the standard headset jack of a mobile device, enabling swiped transactions. Square Customer Engagement helps sellers analyze and understand their businesses, engage their buyers in ongoing conversations, and promote their offerings through e-mail marketing. Caviar offers a food delivery service to help restaurants reach new customers.