Clean / improve / update code

.editorconfig

.gitignore

.metadata

README.md

android/app/build.gradle

android/gradle.properties

assets/fonts/Nunito-Bold.ttf

assets/fonts/Nunito-Light.ttf

assets/fonts/Nunito-Medium.ttf

assets/fonts/Nunito-Regular.ttf

assets/skins/default_1.png

assets/skins/default_2.png

assets/skins/default_3.png

assets/skins/default_4.png

assets/skins/default_5.png

assets/skins/default_6.png

assets/skins/default_7.png

assets/skins/default_8.png

assets/skins/default_found.png

assets/skins/default_unknown.png