I appreciate the attention to the iOS app and the most recent updates.
This feature request is for absolute full screen while reading a resource. I understand that some users may want to constantly have the name of the book at the top of the screen, but not sure how many really want that? When I have my iPhone and I want to read text, there just isn't enough screen real estate to support that bar that is almost 1/6 the size of the screen. This feature seems to be standard on almost all reading apps for iOS these days as it was a much asked for request on many apps.
If there are many users that want to keep the header while reading, then perhaps a toggle in the settings?