Co-founded by Twitter co-founder Jack Dorsey and Brando Arnovick of Mission Minis is a free credit card reader that plus into a phone or iPad. No extra equipment, no contracts, or monthly fees or merchant account required.
2.75% + 15 cents for swiped transactions.
3.5% + 15 cents for keyed-in transaction.
Every credit or debit card they accept (Visa, MasterCard, Amex and Discover) have the same flat rate.