Would be great to sort/filter library and lists by Keywords.
Also select keywords in search box, and search by several keywords (e.g. papers with keywords A AND B)
Along this theme, would be great to be able to select or search on multiple lists using simple boolean logic, such as AND, OR, NOT, etc.
+1 for keywords
+1 for boolean!
Filtering by key words +1
Being able to see what library each paper is in +1
Both of these functionalities were available in Papers3. Please reimplement.