This library (Textile textview) is open source.
Link here.
https://github.com/ShakeJ/Android-Textile-MarkUp-TextView
This textview change markup string and display it.
Textiletextview.setTextileText("markup-string");
very easy.
You download demo application.
https://play.google.com/store/apps/details?id=com.shakej.textile.textview