Yes, but also no. It is more like an AppStore because it offers interactive content (games) that is 100% like what the AppStore already offers and wants to audit and control.
I am not saying that Apple should not allow this in the store, I can just see a legitimate angle as well as the more fishy angle that I mentioned.
Also, if Netflix were to start offering porn lets say, I bet Apple would have concerns there too.
Haven't looked into this for a while, but most projects I saw were using Amazon's API, which I guess has the largest international catalog of books. The typical next result is GoodReads, which would be awkward to lean on for building a competitor.
