JSONtoolkit is a multi-activity tool for manipulating JSON.
Allows editing of JSON properties, adding or removing properties; query using LINQ and TokenSelect to filter JSON. It also allows conversions between JSON and XML.
This tool is useful when working with WebServices requests and responses, allowing you to manipulate JSON from the request/response.
Additionally, it allows you to add a new property, or an ArrayItem to an existing property, which property value to add is an array of values (i.e. "required_documents": ["passport", "utility bill", "other id"]).