Millennials love Square (NYSE:SQ). The next-gen payments processor has made it easy to settle up on transactions. It’s not the only game in town when it comes to cash-free exchanges of funds, but its market is clearly on the ascent. Square’s commerce platform helps upstarts and other indie businesses process payments the way giant merchants do, and the Square Cash app is skyrocketing in popularity. It embraced cryptocurrency before other financial services giants warmed up to the new bitcoin normal.