It's easy to use both the app and plugin. As long as you have FBReader installed beforehand, you can download the plugin and install it without any problems. Again, you need to make sure you install FBReader BEFORE FBReader PDF plugin. As long as you install them in the correct order, you won't have any problems.
FBReader PDF plugin is an essential plugin for FBReader users since there are so many books and documents in PDF format. Thanks to this lightweight plugin (less than 7 megabytes), you can read PDFs comfortably from FBReader on your Android.