I could not download the Pandora app until I deleted my music files (there were many). I will purchase an SD card. I read the manual re: the SD card, I could not see if it's necessary to store particular file transfers on it - or does the device realize internal storage is full and would do so automatically? I do see is Advanced settings downloads can be directed to the SD card, but I wonder about file transfers, such as when I connect the tablet to the pc via USB to transfer music?