Make sure you read the instructions including editing the Kobo eReader.conf file's file exclusion entry
before you install the One Click Package. It's found under the [FeatureSettings] header. If you find [FeatureSettings], just add the second line under the header otherwise add both lines.
Code:
[FeatureSettings]
ExcludeSyncFolders=(\\.(?!kobo|adobe).+|([^.][^/]*/)+\\..+)
You will need to use NickelMenu or KFMon to start KOReader so yes, you need to install more than just KOReader.