Bluefire has just released Cloudshelf, an iOS-version of Readium SDK -based ereader program for ePUBs. Android versions and browser support are coming this summer. Why is this a big thing? Because there really has been a lack of modern multiplatform reader.  Modern means that it can handle ePUB 3, Fixed lay-out ePUB (FXL), Media Overlays, Audio, Video, JavaScript interactivity, animation, etc.

In our initial testing, even FXL directly from InDesign (CC 2015) worked flawlessly. Cloudself is a program to keep the eye on. Perhaps the future ereading projects may find this platform as an interesting option to recommend and even build on.

Link to Appstore:
https://appsto.re/fi/OJes7.i

Readium is an OpenSource Tech for EPUB 3 and the Open Web platform. Initiated by IDPF and architected to work on any modern (HTML5) browser.
FAQ: http://readium.org/about/faq

Bluefire is a maker of Bluefire reader (iOS, Android, Windows) one of the most popular eReaders capable of handling Adobe DRM
http://www.bluefirereader.com/white-label-platform.html

News source:
http://readium.org/news/bluefire-releases-readium-based-cloudshelf-reader-app