Well, Android official TextToSpeech engine is very simple and easy to implement. I played with it for sometime and it is working exactly as it should.
But one disadvantage of this engine, is it only has one fixed female voice and I must say I am not in love with that voice. And from this and this thread, I came to know there is no way to change the voice.
So my question is, is there any other TextToSpeech libraries available which can work with android?