They have been referenced in this topic ESP32 vs C.H.I.P. Microcontroller/processor
And I have managed to install (but not used) both server and client in C.H.I.P. (basicly following RPi install methods) - It is reportedly possible, but not officially supported in Blynk yet. Getting Blynk (client) to work on C.H.I.P. hardware
Aside from some direct Python/Javascript (i.e. I don’t know what it was 
) XIO pin manipulation of a battery monitoring script (non Blynk) I have not yet wrangled proper GPIO support… something I am working on learning, over on their forum. https://bbs.nextthing.co/