ZUGate - provides access to USB drives and disk images with FAT ExFAT EXT2/3/4 NTFS UDF and ISO 9660 file systems. Supports encrypted devices (LUKS 1 LUKS 2 BitLocker TrueCrypt EncFS drive protection formats).

The app doesn't have permission to access the internet so cannot transmit any information to other services or persons.

Your device must have support USB Host (OTG) for access to USB drives. Otherwise work will only be possible with disk images.