MarkAble Audio Book Converter
MarkAble is not free software (I have to make a living, pay the mortgage, feed the cat, etc).
You can evaluate MarkAble free for 5 days. After that, to keep using it, you'll need to pay me the modest sum of US$15. When you do, you will get a registration key which will let you keep on using the software for as long as you like.
Your registration will get you free bug fixes and minor version upgrades (eg 1.0 to 1.1 to 1.2, etc) but I may ask for a further fee if I add major new features and go to the next major version (eg version 1.3 to 2.0). That, of course, will be your choice, you won't need to upgrade if you are happy with the current feature set.
You can purchase a registration key in one of three ways (you take your pick, though I prefer PayPal):
Once you get your registration key, open up MarkAble. From the top menu bar, choose Help, then Register. You'll see this dialog box. Enter your name and registration code like this: (sorry, these numbers are fake and won't work to register your copy!)