I use my PC,
I transfer all images/videos to my external hard drive using
RIGHT CLICK " CUT " then RIGHT CLICK " PASTE " In external
Hard drive, doing this will automatically delete file from card,
as it transfers it to the external HD. ( NOTE: to speed things up
HOLD DOWN " CONTROL ( CTRL ) " key, then highlight all files you
Want to transfer from sd card and you can do multiple transfers at once!
Now if you choose RIGHT CLICK " COPY " it makes a copy of it to
External HD, and leaves a copy in SD CARD, you'll need to open sd
File and use RIGHT CLICK " DELETE " to delete them, ( NOTE: you can
Also use the HOLDDOWN " CTRL " button gimmick here as well!
I believe the only way to delete through APP, is formatting!
Hope this helps!