This may sound like a stupid question. It has been a while since we used our Square reader, (we use it as an emergency back up when our credit card machine is down at our business). We used to use it on a previous cell phone, so how do we use it on a new cell phone with the old phone number? Do we have to install the Square App again? I looked at doing this and it looked like we would have to have a new account. We want to use our old account, but on a new phone. Please could anyone help us out.