I use mantano - a super old version and I really liked it. I dont update all apps automatically as sometimes in the newer versions they break stuff for old devices and my device is old. But the best ereader app is the moonreader one in my opinion. I have had the premium version for while and I think it's a well rounded app with all the features you might be looking for.
I have Moon Reader, Librera, Aldiko, Prestigo, Cool Reader and several others. I know which ones I like; this is just a review series of the various apps out there.