Hi,
I've tried this again with an SBN file. Followed the same process of copying the file from my computer to the phone, an Android phone, stored in the documents folder.
The default file brower could see the file.
Then opened the default web browser. Navigated to KA72. Uploaded the file and KA72 processed the file. It worked fine as the pictures below show.
As the Android OS is based on Linux and Linux is very flexible with its file formats its unlikely there is anything in the Android OS which stops it from reading certain file types. If your device is not seeing the file then perhaps its the way in which Samsung has implemented Android though why would they do this?
It does not look like KA72 has any issues with Android either.
Perhaps contacting Samsung and asking for their advice would be the go.