The free version of NaturalReader has limited features. These include a Miniboard to read text in other applications, being able to work with PDF, Docx, TXT and ePub and a limited choice of voices.
Also available are paid versions of NaturalReader with additional features such as more natural sounding voices, batch convertor of scanned PDFs to text, or the ability to save audio files in mp3.
For OCR option, you can also use Adobe Acrobat Pro to convert scanned PDF files into a text document. To read PDF files protected by copyright, you can activate the Adobe Reader or Adobe Acrobat Pro embedded reading feature. Go to View > Read Out Loud > Activate Read Out Loud.
After you have downloaded NaturalReader, do sign up and create an account, so that your uploaded documents can be stored in the cloud and easily retrieved.
You can change the voice and speed by using the icon shortcuts on the menu bar. Change the speaker by selecting one of the options under "Choose Voice". Change the speed by selecting one of the options under "Choose Voice Speed".