Hi @wu!
Welcome to the ODK forum! If you have a moment, introduce yourself here.
ruODK has just passed peer review, and is being transferred to rOpenSci at https://github.com/ropensci/ruODK. I'm sorting out a few squeaky bits, then we'll announce the release officially.
Let me know if you run into any troubles in the meantime.
Edit: transfer is done, and updated links have been merged into ODK Central.