Well, the HooToo nano arrived.

The first issue was that the tablet is incompatible with the app (old tablet), so I switched to my telephone (Samsung Moto G Play running Android 7.1.1)

Installed the app, set up the HooToo, but it:
Failed to recognise the Elemnt (Disk 1 not installed)
Failed to recognise camera (Fuji) (Disk 1 not installed)
Did recognise an external Hard Disk, so I'm presuming that means that the HooToo is working as it should.

Tried another phone, a cheapy Chinese Cubot. Same as the Samsung

Went back to the tablet and could connect with the Hootoo without the app, but the outcome was the same - disk was not installed.

I also plugged a card reader into the HooToo unit and I could read from that.

Interestingly, the interface ran better on the Cubot rather than the Samsung. Logging in through the app was more often unsuccessful than not and the browser interface was slow and the screen was all but impossible to navigate around.

Since neither phone is OTG compatible I'm back to square 1.

If anyone has any suggestions, I'd be grateful!