I found a good use for the iPhone Mirroring app on my MacBook Air. With a particular banking app it's easier to use the phone app rather than a web browser. I had to pay a tradesman three separate transactions: one of 5% to confirm the job quote, another of 50% to cover purchase of materials and then the final balance.
I had the invoice in the Xero website on one side of the display and the iPhone Mirroring on the other side, making it easier to ensure I had the bank transfer details correct before sending the payment.
It's a great method of working with an iPhone, I hope Apple extends it to the iPad soon.