version 1.18 Play button is added. Banner ad is not shown while playing. Full screen option is added. An interstitial ad is showed when the new game button is pressed. Ad program is changed. version 1.16 The theme option is added in the system settings. version 1.15 The theme is changed. The problem of the screen orientation is fixed. version 1.14 Bug fixes. version 1.13 Fixed the bug that the layout collapses on some devices after displaying interstitial ads.