For an e-book to reach its maximum audience, it needs to be accessible on all modern reading devices in a consistent way. This work compares existing technology choices for publishing e-books for iPad and Android tablets. The research has been conducted in the context of Sophie, software for reading, writing, annotating and sharing networked books, with attention to the ongoing evolution of the software necessary to keep it relevant in a swiftly changing technology landscape. In particular, the article charts the development of the ability to create Sophie projects specifically for a new generation of mobile devices and tablets in support of a generation of students, scholars and publishers who expect easy collaboration, participation and interaction, and tools that allow for media-rich, mobile experiences.