If you hate doing math and you run a small business then surely you've looked longingly at mobile credit card systems like Square's longingly. No handling of cash certainly would make life easier, but Square's system of fees and surcharges weren't exactly easy to figure out themselves. Now the company has simplified things, dropping the $.15 per-transaction fee for swiped purchases, charging a simple 2.75 percent on each transaction. If, however, that transaction is being made without swiping the actual card the $.15 transaction fee sadly comes back, but the percentage fee has gone down from 4.0 percent to 3.5. S