Is there an application that allows you to separate files, and even keep them hidden from applications. For example I want to keep all of my family pictures in the gallery. I don't need any pictures I take for work to end up in the gallery view. I have some different excel files, some for work and some for home. I don't need documents to go to pick up the home related spreadsheets. It would also be nice to lock certain folders from general viewing for privacy when I pass my phone around to people who want to check it out.