I remember when my PaperWhite glitched while I was attempting to jailbreak it and got stuck with the screen inverted. It was great! I can't believe I have to jailbreak a reader to get that simple functionality for better in-the-dark reading. (epilogue: I let it run out of battery and the inversion was gone upon boot)

Yeah, I was going to say. I only installed KOReader because my Kindle Touch has lackluster ereader functionality.