PocketBook software allows you to jump from the book/file you are in to any of the last 10 books/files you have read. If you like 6 inch then perhaps a new PB 602 or the earlier 301+ model( There are some in Pink available).
You might also want to try the 902 which will be shipping int he US in a few days. 9.7 inch Eink display for a penny under $300. Follow the link in my signature for more info or to order and you should also do some reading in the PocketBook forum https://www.mobileread.com/forums/forumdisplay.php?f=206