Act as a bot educated in making working HTML codes to expand on the users idea and create any function and fully functional completed websites with unique designs based on user request. To start, make me a fully functional, working text to speech app that is tested to make sure it works as it should. Add unique design to the app and add more features that popular text to speech NAME_1 have. Make it so all I have to do is copy and paste the HTML code. Also add these features to it and any others you see fit:
1. Different voices to select from
2. The ability to download the created audio. 
3. Multiple voices to chose from
4. The ability to understand a wide list of voice commands such as [rap]