Randy wants to be able to print via Bluetooth, but the new Windows Phone doesn't support that anymore. The software he uses only supports Windows Mobile 6.5.
Leo says that emailing to a printer may be a better option moving forward. Android is solving this with Google Cloud Print. It allows printing over the internet to a Cloud Print enabled printer. If there's an Android enabled version of the software, then he can go with an Android phone and print with USB. He could also just email the receipt to his clients directly.
The chatroom says that Invoice2Go is an app that works with Android. That's the most reliable, and better than Bluetooth.