The beautiful Avatar was designed by Dax Gamma. Please take a look at more of his work here: http://www.daxarts.in
Since Android's built-in Voice is almost a disgrace for a character like Cora, please download SVOX's UK English Voice:
https://play.google.com/store/apps/details?id=com.svox.classic.langpack.eng_gbr_fem
While this will set you back $2.99, you will not regret it. The voice can be used in all Text-To-Speech enabled Android apps.