Text-to-Speech

Read&Write for Google Chrome

https://chrome.google.com/webstore/detail/readwrite-for-google-chro/inoeonmfapjbbkmdafoankkfajkcphgd

Read Aloud

https://chrome.google.com/webstore/detail/read-aloud-a-text-to-spee/hdhinadidafjejdhmfkjgnolgimiaplp

Voice Instead

https://chrome.google.com/webstore/detail/voice-instead/kphdioekpiaekpmlkhpaicehepbkccbf

You can see more details on each of these in a the following blog post

http://www.controlaltachieve.com/2016/10/special-needs-extensions.html