[sovre]

I have an audiobook with 48 separate m4b files. All are numbered correctly with chapter titles, and if I listen to the book using itunes, for example, the files appear in the proper order.
However, I would like to listen to the book using the audiobook app on my iphone. There is just one problem: when I transfer these files to my iphone, it appears the chapter order is not preserved but gets completely disorganized.
The book starts up in the middle rather than at the beginning.

From the little technical knowledge I have I'm assuming this is a metadata issue - the files aren't properly numbered in the metadata, so the iphone app can't process them in the proper order.

Is this correct, or would this instead be caused by another issue?

If it is a metadata issue, is there any software out there that can quickly and easily insert metadata for the chapters?

itunes of course allows me to give individual track numbers to each file, but I dread the idea of doing that for 48 files!

Thanks for your help.