Haven't tried so only 4 I love the FBReader app & plugins but I haven't actually been able to use all. I don't currently have Calibre installed & running on a desktop to use this but plan to. I have no djvu type books & have never seen any. Still  everything is great. IDK tho  I got the paid version & wonder if this  like other plugins  is now built in.
September 10 2015