Square
Square is an Android app that enables you to accept mobile payments from your phone. This app is particularly useful for anyone who does business away from a traditional office or retail environment, such as mobile food vendors, sales reps who sell products at shows or in customers’ homes, or conference speakers who offer back of the room sales of products related to their presentations.
When you sign up for Square, you receive a free credit card reader by postal mail that you attach to your Android phone (see Figure 4).
Figure 4 Accept mobile payments from your phone.
Square requires no contract or merchant account and doesn’t charge a monthly fee. Instead, you pay a 2.75 percent swipe fee each time a customer uses Square to make a payment.