CitiesDirectory means a full Android application solution for multiple city directories with a backend system.

1. Android Application: A user-friendly mobile app that allows users to browse and search for information about various cities. This could include details about local businesses, tourist attractions, restaurants, hotels, events, and more.

2. Backend System: A central server or backend system that stores and manages the data for the city directories. This system is responsible for storing, updating, and delivering data to the mobile app.

3. Database: A database to store information about the cities, such as business listings, reviews, ratings, and any other relevant data.

4. User Management: User registration and authentication to allow users to save favorites, leave reviews, and contribute content if necessary.

5. Search and Filtering: Robust search functionality to allow users to easily find the information they need, possibly through filters or categories.

6. Maps and Navigation: Integration with mapping and navigation services to help users find directions to specific locations within a city.

7. Reviews and Ratings: Users can leave reviews and ratings for businesses, which can help others make informed decisions.

8. Push Notifications: Optional notifications to inform users about special offers, events, or updates related to the cities in the directory.

9. Content Management: Tools for administrators to add, edit, or remove listings and update information about the cities.

10. Data Synchronization: Ensuring that the data in the mobile app is up-to-date and synchronized with the backend server.

11. Analytics: Gathering and analyzing user data to improve the app's performance and user experience.

12. Monetization: Options for monetization, such as advertisements, premium features, or partnerships with local businesses.