Adaptive background
Viewed images are displayed on especially generated background, when possible, which boosts their reception by smoothing composition
Navigation slider
Not only You can change images by using hotkeys, You can do so by using slider to just slide across collection.
Smart image adding
When You add directories those are not only searched in top level, but recursively as well.
Bookmarks
Keeping track of viewed content is easy when using bookmarking feature. It can remember last viewed position for given collection.
Let it say
It can use speech synthesis to inform on actual page number, read chapter and even content title if recognized.
Download, less
than 120 kb