I am Oyster subscriber. Their app is pleasant to use. I do miss a little more organization, but I am fine with it overall.

It is heavily curated ie. you get a lot of suggestions. And since they have rather limited selection, this is great. I managed to read through 3 books already and have a queue of several. I noticed that some were from Gutenberg project, so I guess they will not have to pay for those.

Overall I like experience and will continue to use, as well as Amazon and piratebay and other services to get myself books.

Only thing that might turn me off is, they have limited selection, but they can remedy that while I am going through books already available.

I really need them to come up with good Android app.