Since our app uses the built-in iPod Music controller, we activate all the same features that the Music app does. So, your example of showing the album art on the lock screen does in fact work.
This is different than different category apps, like Safari replacements, that can't take advantage of all the built-in controls/features outside of the app.
(I work for szello)
It's the same issue I have with the AirPlay icon on the iPhone lock screen; it is right beside the forward icon and I am ALWAYS hitting forward instead of my intended tap on AirPlay. When you're listening to a two hour podcast, this is very frustrating.
(Yes, I'm aware that you can navigate by album name, but who remembers all your album's names?)
Whether it's an audiobook or music, I'm hitting the play and pause buttons all the time. I don't have particularly thick fingers, but my genius self still manages to accidentally hit the Back or Forward button's instead of Play or Pause about 2 times out of 10. In an audiobook, loosing your place and finding it again is a killer, especially if the book is split into very long segments of audio.
Minor nitpick on a device with such large buttons, but I just find that idea annoying. Could be just me and my obviously adroit digits though :p
You're right though, an app especially for audiobooks with bookmarks, notes, etc. would be great.
Thanks for the feedback!
The app's App Store page on the the other hand is much more pleasant.