2008–2011
2011-present, 2011–2014 (Android), 2011-2015 (iOS)
In 2011, the logo was given a more basic and flat look. First debuted in developer's versions in March 2011.
2014-present (Android), 2015-present (iOS)
In 2014, the gradients were removed on the logo for the mobile application version on Android Version 5.0 Lollipop.