I just downloaded the ap on Saturday to use at an outdoor roadshow on Sunday. Instructions for setup were good and it was easy to navigate. I had one small glitch (a setting in my Authorize.net account). The iPhone would show the transaction as declined but it was being approve and recorded by authorize.net. I emailed Spartadata...and I received an email back a few hours along with a phone number to call. I spoke with Mike who proceeded to troubleshoot and fix my setting with 2 hours (remember this is on a Saturday!) I am extremely pleased with the functionality of the program and the extraordinary customer support.