This is a pretty cool concept. Portable, wireless scanner by way of your cell phone.
When I first started the scanner, it seemed to work fine. The barcodes were scanned and they showed up in the app. But when I opened Notepad and scanned some barcodes with Notepad in focus, they barcodes did not get typed into Notepad. I eventually switched to "Continuous mode", and the barcodes were typed in Notepad upon scanning. Then I switched to the TD and it also worked just fine. I began to think maybe it was "Single scan" mode that didn't work, so I opened it back up, went into Single scan mode, and scanned a barcode. It was typed into the TD as expected. I have no explanation for why it didn't work at first, but after the first successful scan and entry into Notepad, everything just worked.
I'm not sure why it isn't working for you. The app and server definitely work as advertised.