I'm there with you. I still really like my S7e, and don't plan on spending another $1000 just have the very latest Samsung flagship. I might feel differently when the S9 or Note-whatever comes out in another year or so.
I use Moon+ Reader for much of my LG V10 reading.
The paid pro version is worth the money.
I'm too new to post a link to the Play store, so you'll have to search for Moon+ Reader on your own.