List building Nook, Kobo, or Smashwords readers

Are there list building methods for platforms other than Amazon? I’m looking for something like The Fussy Librarian, BookDoggy, etc., except for Barnes and Noble, Kobo, or Smashwords. I need some new science fiction and high fantasy readers who shop off of Amazon. I’m using Story Origin, but even the wide authors there don’t seem to have many wide readers. I’d appreciate any suggestions. Thank you!