isomorphic-jsonp

Based on jsonp-client. See basic description there.

Key differences

Removed "fs" dependency from serverside module, so it can be safely included in clientside build. And so removed ability to read files from filesystem (don't know whether it can be needed in real app. It seems it was introduced only for testing).
Promises
No multiple urls or array of urls (why it can be needed at all?)
Removed hack for attaching superagent-mock.
little sugar to allow to pass query parameters as object

$ npm install isomorphic-jsonp