Please have a look at the Wikitude Forum.
Your question was answered there already (quote from user "Caroline")
"The Wikitude Plugin is a Phonegap Plugin. Phonegap Plugins add native (for Android: Java, for iOS: Obj-C) code files to your project. This native code supports functions you can call from within your hybrid code. Therefore, your hybrid code remains hybrid, but before deploying to different platforms, you should provide the Phonegap Plugin (such as Wikitude Plugin) for that platform as well. "