I am having the same issue. I bought Ematic EGM003 tablets using Android 4.4.2 to use for scanning bar codes for an event I host. I go to the Google Play store, find the free Codereadr app and click Install. It then says I have no devices. Then a screen pops up saying "You have not accessed the Google Play Store App (the white shopping bag icon) on your device with this email account. "
I have set up my Gmail account on the device. I have made a purchase of a song that wasn't free so I have made a purchase on the device.