Here's an example of a custom JSON connector Visual Studio project for a QlikView connector that reads a JSON file directly into QlikView.
I downloaded the QvxSDK and I modified one of the the examples to read a JSON file. I did not find an example and very little info on how to read a JSON file into QlikView so I "examplified" connector from the production environment and now share it.
To modify the connector you need Visual Studio. To test it, you need to copy the connector files (found in the folder "JSON Connector Example\bin\x64\Release") to a folder in C:\Program Files\Common Files\QlikTech\Custom Data". Most likely you need to create this folder.
Look at the QVXSDK and http://www.newtonsoft.com/json for more detailed information.