Unity iPhone plugin - what data type to use?

I’m integrating Countly iOS plugin with Unity. I’m following Unity - Manual: Building plug-ins for iOS and its example: http://docs.unity3d.com/Documentation/Images/manual/iPhoneNativeCodeSample.zip

I’ve got most of the things done - I can call start() and 2 recordEvent() overloads and they seem to work fine. But calling recordEvent() with segmentation seems to break something in my application (other objects behave weirdly) and these events never show up in the Countly’s Dashboard.

My guess is that I’m using incorrect type for the dictionary data in parameter. I.e. objective c’s NSString * I change to const char * (see Bonjour example) and then it translates to string, int translates to int but what does NSDictionary * translate to? How to I receive this argument type from C# code?

The way I would do it is to translate NSDictionary to a string based format such as JSON and pass it between ObjC and C#