Update README.md

README.md

@@ -4,6 +4,7 @@ Lightweight and flexible cross-platform game engine.
 I'm an independent developer and your contributions are invaluable to me. If you like the work I do, please consider supporting Crown development by means of a small contribution. I'm also available for hire to work on or with Crown or somewhat related technologies/projects.
 
 [![PayPal](https://www.paypalobjects.com/en_US/i/btn/btn_donate_LG.gif)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=6FQMPUQQ8KQKW)
+[![Flattr](http://api.flattr.com/button/flattr-badge-large.png)](https://flattr.com/thing/4945485/Crown)
 
 ##What is it?