Hi Notechsavvy and welcome to Android Forums. I'm guess you might have to dnld a file viewer that will do .snb files from the play store but I'm only guessing. You might want to check in with the friendly members that use your S3 to see if they have any insight. Here is a link to the S3 discussion area. Just ask in there and someone will help you.
Samsung Galaxy S3 - Android Forums
Thanks for joining our community and I hope you enjoy your time here.