(This readme will be changed soon, at the moment it's used as the index page for documentation: http://incendo.ws/projects/InfoStats2/)
InfoStats 2 is a far better implementation of the original InfoStats. It allows both HTML/JS and Objective-C developers to access various information, and to call system functions without the need for reverse engineering. In short, it's a powerful, easy-to-use API.
At the bottom of this page can be found references to all the classes that make up this API, along with their constituent methods.
HTML
For the HTML side of things, Cycript is injected into all instances of UIWebView within SpringBoard (hence the dependency on Saurik's WebCycript). As a result, any function provided by InfoStats2 is accessed via Cycript, which is completely native alongside JavaScript code.
To make things even easier, examples for using each of the many parts of the provided API can be found here: examples.zip.
Also, a quick, no-nonsense guide to Cycript and this API (recommended reading) can be found here.
Objective-C
For those using this within tweaks, retrieving data is as simple as calling class methods; there is no need to allocate an instance of anything. Additionally, there is no need to link against InfoStats 2 to obtain data from it, simply get its class via the Objective-C runtime - eg, objc_getClass("IS2System") - and call whatever method you need.
Headers can be found here: headers.zip.
iOS Version Compatibility
A major advantage of using InfoStats 2 in your projects is the fact that it supports all version of iOS from 6.0. As a result, you do not need to worry about updating your own code in relation to changes internally in iOS; this library handles it for you.