Smart AudioBook Player - Smart AudioBook Player app comes up with features to help you in casting all your audiobooks to Chromecast enabled devices so you can enjoy them with your friends and family members.
Macsome Audiobook Converter - Convert Audible Audiobook to MP3 / AAC at up to 300x faster speed and id3 tags kept.
Voice - Convert texts to audio files easily... Write your text, click export.
TunePat Any Audiobook Converter - TunePat Any Audiobook Converter is an excellent Audible audiobook downloader designed for downloading and converting audiobooks in AA & AAX format from Audible to M4A/M4B/MP3 format.
LibriVox - free public domain audiobooks
TunesKit Audible AA/AAX - Audible AA/AAX Converter by TunesKit is an application that enables you to convert audible AA and AAX files to the formats that are supported by other devices.