I think there are several issues/problems going on with audiobooks and iOS8.
1a. People are having an issue 'syncing' or adding audiobook tracks to devices with iOS8
2a. People are having an issue changing an MP3 to an audiobook in iOS8
3a. People are having an issue playing an audiobook file on iOS8 devices
The first two seem to have easy solutions:
1b. Change the folder where audiobook is saved (from the audiobook folder to music folder or any other folder on your computer). You can also not 'sync' the device and drag and drop the files to the phone (make sure that on the device under the audiobook tab that the ''sync" feature is turned off
2b. highlight the file in iTunes, right click, get info, click on file type change to audiobook/remember playback position
I'm having an issue with #3 - the files are mp3's - I have converted from default 'music' to audiobook (see #2b) and have been able to get the audiobook file to the iPhone (see #1b)
When I play the file in the stock music player it does not play at all and quickly scrolls through all audiobook files for that book. Even closing the music app i find the phone gets hot and slows until i do a complete power cycle (turn phone off and on again)
I am not at my home computer so I will have to wait but I have found three possible solutions which I will try tonight:
1. Change the files from 'audiobook' (see #2b) to 'podcast or music' files this solution is annoying because the file will be categorized wrong and not showup in the audiobook folder, however I can still have it labeled to skip during shuffle and remember playback position.
2. I saw an audiobook app in the itunes store that said there was an issue with iOS8 and audiobooks with images... strange but could be a simple solution. follow the instructions on #2b go to artwork tab, select the artwork and delete it, (if needed delete the files from the phone and resync or drag and drop) This solution is annoying because now there is no artwork with the audiobook
3. Third party app - I haven't found a third party app that actually plays 'audiobooks' (files labeled audiobook and show in the audiobook folder in iTunes) There are a lot that play music files (they can be audiobooks but are not labeled that way) this is annoying because if there is an app that plays these files it is most likely not free, so I'm paying for a feature that should be native with the device/software
I'm not sure if any of this makes sense, and i'm actually writing all this out as a reminder of what to try when I get home - I will try and report back when I find out.