iBook Author Alternatives

Good Morning,

Like many Apple users, I was frustrated by the decision to abandon iBook Author, and I am especially irritated that Pages has not been updated to include the various functions and tools that I loved in IBA. I am a teacher, and I created several short books for my classes, and one of the tools that really helped my students was the pop-up dialog box. I also miss the ability to make text interactive. When reading a play by Shakespeare, students found it helpful to be able to hover their pointer over a vague phrase and see a quick explanation.

Since Apple clearly does not intend to bring these widgets (and others I could suggest) into Pages, does anyone know of an alternative application? I've played with simple apps like Book Creator, but these are clunky and better for younger audiences. I imagine Adobe's InDesign would meet my needs, but there is a huge learning curve there. Any suggestions?