Are IoUtils still available?

I would like to save/read json files: http://docs.bela.io/namespaceIoUtils.html

but they don't seem to be in the libraries section of the IDE. Am I looking in the wrong place?

they are actually in core/ and include/ as they are used by the core, so the include is simply #include <MiscUtilities.h>.

You may also use the JSON class. Similarly, this is not currently libraries, so you only need #include <JSON.h>

Are there any examples of how to use JSON::Parse?

not too many. Some here https://github.com/BelaPlatform/Bela/blob/master/libraries/Scope/Scope.cpp and then in some of the examples:

Trill/general-settings/render.cpp
Trill/craft-visual/render.cpp
Trill/multiple-devices/render.cpp
Trill/flex-visual/render.cpp
Gui/frequency-response/render.cpp
PureData/custom-render/render.cpp
PureData/custom-render-ultrasonic-distance-sensor/render.cpp

Thanks, was a bit too cryptic for me to figure out but I managed to get this working pretty easily: https://github.com/nlohmann/json