1.5.5
  * wiki page on the website created, describing how to create new levels
  * 12 more winter levels added
  * display for the percentage of incremental achievements added
  * added the time to the display on the screen

1.5.4
  * added translators to the credits-screen in the game
  * added Dutch language (thanks to Heimen on weblate)
  * added Galician language (thanks to Iván on weblate)
  * improved Spanish translation (thanks to Markel on weblate)
  * removed transparent pixels from screenshots

1.5.3
  * added adaptive icon (Android 8 and higher)
  * disabled background zoom near the apple
  * added Norwegian language (thanks to Allan on weblate)
