Kudan is described as 'Highly configurable, augmented reality SDK with markerless and marker operation' and is an app in the Development category. There are three alternatives to Kudan for a variety of platforms, including Windows, Linux, Mac, Android and Chrome OS. The best alternative is ARToolKit, which is both free and Open Source. Other great apps like Kudan are Vuforia (Paid) and MyWebAR.com (Freemium).
Transparent, Modular Code Delivered Through Open Source Complete access to the computer vision algorithm allows you to modify the source code to fit your specific application. Freely distributed for use under a LGPL v3.0 license.
A more powerful way to engage, leading global brands use the Vuforia mobile vision platform to deliver unique, entertaining and interactive mobile experiences that transform the way users see and use brand apps.