Version 2.2.0 is now available for download.
It supports the Paperwhite 5.3.0 Firmware, addresses most of
NiLuJe's PW comments, and includes a few other minor fixes to make the UI more usable on the Paperwhite.
Note that the search functionality has been completely dropped for the Paperwhite (it's still available on the Touch, though).
Oh yeah, one final rant @Amazon: