We would like to know if there are any POS in the market that accept BTC or any other Cryptocurrencies? How do you think if these kinds of POS will be the trend in future?
Yes, depending on what country you are in. A quick check of Big Internet Search Engine for the term "Bitcoin POS" finds me two top of the list answers, once country specific with invoicing, payment and POS and, the other a global.
Yes. General Bytes, the manufacturer of ATMs and POS in the Czhech Republic has several in action in Prague.
I hope that Lightning POS will be the new standard though. There are a few companies working on that too.