Include extensions for Chrome and Firefox web browsers, which read the web page text out.
Include a toolbar for Internet Explorer web browser, the toolbar can read the text on the web page out, and convert the text to audio files.
Include a toolbar (add-in) for Microsoft Word, the toolbar can read the text on the Word document, and convert the text to audio files. (Show the toolbar.)
Adjust audio files' sample rate and bit rate to obtain satisfactory audio quality or audio file size.
Allow users to customize user interface window layout, font, text size, text color, highlight color, and background color.
Allow users to adjust voice speed, volume, and pitch.
Keyboard shortcut keys.
Speaking repetition.
Play music when it finishes reading the text.
When convert a batch of files to audio files, here is the easiest way: on the menu bar, click File->Read Batch Files, next click Options->Settings.... On the prompt, click Audio Output on the left, select second option on the right, and specify the folder where you want to save all the audio files. Doing so, all files will be saved in that folder automatically, avoids repeated clicks for choosing where to save the audio files.