Mulitsite Installations?

The free version can be used on multisites: Their limited features has no effects on this.
With the PRO-Version you can store Templates in the database for using it on multiple pages / blogentries. As these Templates are stored site by site multisite Management comes into the game. PRO-Versions prior to 2.0.9 do not support multisite. Versions after 2.0.9 are multisite ready.

Thanks to Rod from Canada and Layth from Australia!

Version 3.4.8 (April 29 2018), see in detail here:

Admin error message, if database-update from version 3.4.7 on requires a deactivation-then-activation of the plugin.
Code for using CURLOPTIONS (esp. HEADER and POSTFIELDS) completely rewritten: If you use CURL-POST/GET-API-Requests and CURLOPTIONS check if all is ok, please.
New Shortcode-Parameter: maskspecialcharsinjson=no switches off some usually very good handling of JSON (rare JSON needs that)
New Shortcode-Parameter: httpstatuscodemustbe200=no accepts that some APIs deliver valid and usable JSON and and http-error (ok is 200). Without that the plugins says: No http-ok from the API, hence ignore JSON.
Several Bugfixes: Templatemanager, sorting JSON with twig-extension, use of CURL-Options

Version 3.4.7 (Feb 25 2018), see in detail here:

Building API-URL: twig-code possible in "url". Pass GET-/POST-values to URL. The new Shortcode-Parameter "urlparam4twig" defines, what Input-Names are passed to the Plugin.
Improved Template-Manager: Put most of the Shortcode-Parameters into the Template. So you can call the API by [jsoncontentimporterpro id=NO] avoiding a long list of Shortcode-Parameters
Support of jsonrpc-feeds
If JSON contains special characters like a dash, dollar etc. those are masked in JSON. Hence the twig-template must use these masks like "_symbol_slash_" or "_symbol_at_"
new twig-extension: "converthex23ascii" available, e.g. needed for some JSON-data coming along as hex-data.
Minor bugfixes

Version 3.4.6 (Dec 30 2017), see in detail here:

building API-URL: twig-code possible in "urladdparam" and "curloptions" - e.g. set datestamp in URL
creating custom posts out of JSON: twig-code possible in "customfields" and "title" (both part of the JSON needed when creating)
new twig-extension: "base64encode" available, e.g. needed for some API-authentication (then to be used with twig-code in curloptions)
Minor bugfixes