If you want to type something in Sinhala, this is a good web based tool for use.
The top most text box is for typing in singlish. Look to the right to see a list of helpful combinations. Then the middle box contains the words in Sinhala unicode. This is the format you can use for commenting on web pages, posts to facebook or anything that goes in web as characters. For use in image programs like Paint, PhotoShop or Corel Suite you have to use text appearing on the bottom box with the heading “In Sinhala Font”.
Website URL is : https://sinhalaunicode.gishan.net/write
Write in Sinhala – A web based tool