Version 10.9 (July 25, 2021):
+ Upgrade some utilities.
Version 10.8 (May 25, 2021):
+ Fix level loading error on Android 11.
Version 10.7 (February 21, 2021):
+ Fix error receiving Ruby when viewing ads on Android 11.
Version 10.6 (October 30, 2020) ):
+ Minor upgrade.
Version 10.5 (September 4, 2020):
+ Fixed user-id registration error.
Version 10.4 (May 28, 2020):
+ Fixed some bugs.
+ Add "Watch ads - get Ruby" feature.