Is it possible to access the program on my Samsung phone? I would like to have the ability to send an invoice from my phone.
Yes, you can access this application on Android as well, because it's compatible and available in the Play Store application. You can either use the Store app in your phone or use the link below, log-in with the same email attached to phone and proceed with the installation.
Download: https://play.google.com/store/apps/details?id=com.nchsoftware.expressinvoice_free