usb host mode - What are the limitations of USB On-The-Go on Nexus tablets?

I'm thinking about using USB On-The-Go to extend the rather limited space on the Nexus 10 tablet. I've read about it, but I'm not sure on where exactly the limitations of this approach are. I know that I need a USB OTG cable for it, but I read some conflicting or vague information about other aspects.

• Do I need a specific app? My impression is that I need the Nexus Media Importer, which is a paid app, but is that the only way?


• Which filesystems are supported?


• Can the Nexus 10 deliver enough power through USB to use a portable hard drive, or does it only work with USB flash drives?


• Can I access the external USB drive without restrictions as if it was an SD card, or are there any additional restrictions?