Google Text-to-Speech is a screen reader application developed by Google Inc for its
Android operating system. It powers applications to read aloud (speak) the text on the screen. Currently, the supported languages include Bengali(Bangladesh), Cantonese (Hong Kong), Chinese (China), Dutch, English (India), English (United Kingdom), English (United States), French, German, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese (Brazil), Russian, Spanish (Spain), Spanish (United States) Thai (Thailand), and Turkish (Turkey).
The latest version of Google Text-to-Speech (TTS) brings new languages, and the ability to speak selected text from within any app, across the Android UI.

Version 3.9.6 of the app isn't available on Google Play yet, it is currently bundled only with Android N Developer Preview 3, however, it offers full functionality if installed on Marshmallow(6.0)
The floating text selection toolbar introduced in Android M shows a pop-up box with various options like cut, copy paste, once any text is selected. There is also an overflow menu which houses apps like Google Translate, Assist, Wikipedia, Search, and now even Google TTS.
With this version, Text-To-Speech will show up as an option in the floating toolbar called Google Text-to-Speech Engine. Once the option is selected, the text will be read out loud through the smartphone. An advantege inckudes helping users learn pronounciation of certain tricky words, and even consume TLDR articles without looking at their smartphones.
Also assiatvthose who don't want to type for long. It comes pretty handy.
If users want to change the rate of speech, languages, voice sets, and more, they'll have to do that separately via Settings>Language and Input>Text-to-speech output.