Moon+ Reader Pro is having a 9th anniversary sale. It is 50% off for the month of August.
This a very popular eBook reader, rated 4.6/5 and has been installed 500,000+ times.
If you find you don't like it the developer offers a 30 day money back guarantee. (See the app description.)
If you're not sure, you can first try the free/ad-supported version, Moon+ Reader.
Thanks. Had this through Amazon but wanted to get it from the Play store seeing as I have piles of free credits from surveys.