Cross-reference previews and links in iOS.
I'm going to add a couple suggestions for study features that would be great in the iOS app, since the bulk of my usage will be on an iPad. Some of them already exist in the web app.
In the web app, clicking a cross-reference allows for a preview of the verse, and then there's an option to click through to view it in context. It seems like a pretty great solution.
However, it's absent in iOS, which can be a deal-breaker when using eBible on a mobile device in place of a bible.