Folks,
I use my LG gpad for quite a lot of my activities so I started to search for an Android app that could flash and read the Nanovna firmware using the USB OTG function.
I found 'STM32 Utils' and 'Zflasher' on the Play Store but they were older apps and limited in functionality.
On GitHub, I found an old project from 2015 but although it claimed to flash dfu files, I could not get that to work although it was able to erase the flash while in dfu mode.
Yesterday, I went back to the Play Store and there were two new apps there from the same author. One is completely free but uses the STlink interface to flash and read hex files (I verified it works well).
The other will flash dfu files, is easy to use but has a limit of 25 flash operations before you need to spend to get either 100 more flash operations or unlimited access. This utility works very well except for the cost after the first 25 flashes, so you might want to pick up an STlink interface and use the totally free app.
Please note: I have no relation with the author of these 2 new apps but I do know there are a number of Android tablet and device owners in the forum that can make good use of either app.
I will be making a dedicated cable for my STlink that uses a 4-circuit stereo jack as you only need 3v, gnd, clk and Dio to flash with the STlink. That way I don't need to lug around a laptop...I can use my tablet or phone with my Nanovna devices.
... Larry
