Runtime supports Android Neural Networks API as a frontend. We provide the whole NeuralNetworks.h implementation. Its source code is located at runtime/onert/api/nnapi.
So users can just use NN API in the same way as the official guide, but should watch the version of NeuralNetworks.h. It may not be the latest. There is a copy of the file is located at runtime/nnapi-header/include/NeuralNetworks.h.