It would be a great idea to implement an extra layer of protection to be able to hide certain files or be able to lock them with a set password within the app since I experience multiple users on multiple machines of mine being able to access most of the files. Therefor I would really benefit from a folder I can lock with my personal password and therefor hide sensitive information or files that should not be accessed by other users but me. I would suggest calling it something like Vault or Hidden Files. This could also be done via integration through the apps, let people decide if they want to install the vault feature or not.