Is there any documentation for developing IO bindings? We are interested in developing a mobile speech recognition box for older people. I think it would not be very nice to use the REST-API in this use case, because the box should be able to react to openhab events.
There is no such thing as an “IO binding”, most stuff in io packages is pretty special and cannot be easily put into a generic tutorial.
But if you want to do voice recognition, you might be interested to join in this discussion.