Hydrocarbons and Amino Acids on Android

I continue adding my apps to the Google Play. Recently, two chemistry apps appeared there: Hydrocarbons (Android):

and Amino Acids (Android):

They are not the exact copies of their iOS counterparts. There are several major improvements:
1) There are no IAPs: all questions in Hydrocarbons and flashcards in Amino Acids are available for free. And both apps are free as well.
2) There are new multiple-choice modes that cover all compounds and provide a nice variety to the existing letter quizzes.
3) Both apps are brought to the latest standards of my quizzes: 14 letters, scalability of all elements, a different layout of the main menu.
4) There were multiple fixes and changes in localization, icons, and so on.
5) In my all Android apps, the language can be chosen in the game Settings rather than in the device Settings that is much more convenient and looks very nice.

The same updates will come to iOS in due time. All other quizzes will be added to Google Play soon. I am updating the corresponding parts of this site and I am always glad to hear your suggestions and ideas about my apps.