Plague Inc. is an online mobile game, mix of high strategy and terrifyingly realistic simulation game, your pathogen has just infected 'Patient Zero', now you must bring about the end of human history by evolving a deadly, global Plague whilst adapting against everything humanity can do to defend itself, is free to play on Android devices.
Download the game at:
https://play.google.com/store/apps/details?id=com.miniclip.plagueinc