This plugin has 2 page elements.
'read JSON' and 'modify JSON'.  

When you want to read data, or display it, or work with in on the page use the 'read JSON' element.  You place one unique element on the page for each piece of data you want to work with. For nested lists/arrays see example app.

When you want to modify JSON text for saving, etc. You place one or more elements on the page and trigger the modify workflow

Each element has two input fields 'input JSON' and 'key'.  

input JSON
The json data you want to read from or modify

Key
Location in the JSON you wish to read from or write to. Read documentation see example app for more info

The JSON read element
has many different outputs each associated with (a) different data type and (b) if it is a list value or not. This allows you to connect many different elements and expressions to properly match the output of the read element.  **The output is automatically determined by the JSON parser based on the formatting of your JSON This behavior cannot be changed at present.**. You should know what data type to be expecting. JSON Dates, for example, are stored as strings and read as strings with the plugin.