I like YANG Explorer. (use apple OS computer or linux. I used Ubuntu, and
chrome. Windows and firefox I recall seeing minimal functionality but
shooty, so don't)
... a couple sites for assisting with getting it installed and running...
I also found the Cisco DevNet Sandbox devices useful for explorer and
learning about automation building blocks like netconf/yang. I ran
yang-explorer across the internet directed at the devnet sandbox csr1000v
I think there is another tool called ncc (netconf client?) on github that I
haven'r explored yet.
I was going to try MG-Soft's tool, but haven't gotten around to it.
Similar to YANG explorer and also from Cisco, it allows you to pull all the yang model supported by a certain device (end device or orchestrator like NSO)