We need more options for searching and sorting through various lists - TBRs, recommendations, bibliographies, challenges, whatever. Average rating and number of ratings are the big ones, but you have so many ways that books are being categories for your recommendations engine that it's a shame we don't have more access to customize our results! Also, please make the filter menu that's available at the TBR screen on every book list! I really wish I could sort author pages by theme, pub date, or popularity.