As for the Android NanoVNA WebApp (APK off-line version), it now works with
USB-C Android 7.0+ devices that wouldn't work with my other NanoVNA.
NanoVNA-H has the USB-C 1500 ohm resistors installed so I guess if I want
to have my other NanoVNA recognized I'll have to install the resistors manually.
I insert a small USB hub:
so not direct USB-C to USB-C. That hub is not ideal,
because it does not recharge the Android host while it runs NanoVNA WebApp APK
So before purchasing any bad ESN device do a web search and ensure it supports OTG.
FWIW, while Galaxy Nexus nominally supports OTG, the next generation Nexus 4 does not.
Oristo