Which two functions can be customized for the Salesforce Mobile App?

The customization of the Salesforce Mobile App focuses on enhancing the user experience on mobile devices. The navigation menu content is a critical area that can be tailored specifically for the mobile context. This allows organizations to streamline the information and functions that mobile users access, ensuring that only the most relevant and frequently used features are available to them. By customizing the navigation menu, users can quickly access the tools and data they need, improving productivity and ease of use while on the go.

The other functions, such as custom objects, object compact layout, and object record types, play important roles in the Salesforce ecosystem but do not directly pertain to the specific customization scope for the mobile app's user interface. Custom objects are more about defining new data structures, compact layouts pertain to how records are presented but not directly customizable within the mobile app’s navigation, and record types define the different types of records an object can hold but do not alter the app's navigation experience. Thus, the navigation menu content is indeed the area where customization has the most significant impact on mobile user interactions.