After you've added the buttons, make sure to customize them to your own needs — change the language, the size, or the design of your button.
1. To change the language of your app button, click on the Language menu in the Action tab and select the language in the dropdown:
2. To change the appearance of the button, go to the Style tab in the settings of the selected item:
3. Depending on which platform your mobile app is designed for, you can choose a relevant button type:
4. Also, in the options below you can choose a proper size of the element — Large, Medium, or Small:
5. Publish your site for the changes to appear live.

Tip: if you want to track how many times visitors of your website click on the apps buttons, follow the steps in the article Button click tracking.