I really hope they have a web based API, not requiring a native app. If they do, we would love to use them for our PWA (https://usebx.com) as a bunch of customers ask for this regularly.
Yes -- we have both native APIs (iOS and soon Android), and a web based API (JavaScript). Our JavaScript SDK is designed for you to easily extend an existing web-based application to enable in-person payments.
We’ll be expanding support for businesses in other countries throughout 2019. If you submit an interest form for the beta on stripe.com/terminal, we’ll be sure to let you know when we’re in the UK.