Since the introduction of cloud-based POS systems in the UK in 2002, many of the systems were used on industry-grade touchscreen PCs.
Around the time when tablets and smartphones became mainstream (iPhone was released in 2007 and iPad in 2010) a new app-based card reader was launched in 2010 by Squareup in the US. This was called Square Reader and enabled merchants to use their smartphone as a mobile point of sale accepting card payments with the attached credit card swiper.
A couple of years on, many cloud POS systems were compatible with consumer-grade mobile devices including iPad and Android tablets. The mobility and flexibility of these systems were part of a general trend to make business tools more accessible to micro-merchants. Smartphones got smarter, card machines more affordable, and POS systems less intimidating with the easy software setup.
Great advantages of cloud-based tills are that users have access to the system any time and anywhere, and that data and functions are backed up, maintained and updated by the software provider. And the better the analytical data is, the better business decisions you can make on the spot.