Example of Xamarin.Forms app to converter text to speech - http://julianocustodio.com/TextToSpeech

MainPage.xaml.cs

using System;
using Plugin.TextToSpeech;
using Xamarin.Forms;

namespace TextToSpeechDemo
{
	public partial class MainPage : ContentPage
	{
	    public MainPage()
	    {
		InitializeComponent();
	    }


	    public async void ButtonClick(object sender, EventArgs e)
	    {
                if (!String.IsNullOrWhiteSpace(Texto.Text))
	            await CrossTextToSpeech.Current.Speak(Texto.Text);
	    }
	}
}