Originally, when two people wanted to engage in sexual relations, they had to first meet and then have a requisite date or two before finally getting down to business. A new wave of mobile apps wants to do away with all that hoopla. The apps aim to bring two — or more than two if that’s your fancy — people together just by hitting a button. No strings attached, no wooing necessary. Ross Reynolds talks with Kevin Roose about this market and what it means for safe sex.