Create a 2D pixel art building game where users create pictures by filling a grid with colored squares.
The app should have the following core features:
1. **Template Gallery:**
* Display a gallery of pixel art templates.
* Each template should show a preview image of the final artwork, its name, and the "GameBux" cost to unlock it. A few simple templates should be free to start.
* Mark templates that the user has already completed.
2. **Building Screen:**
* When a user selects a template, they are taken to a building screen with a blank grid.
* A color palette with all the necessary colors for the artwork should be visible.
* A reference image of the completed artwork should be displayed.
* The grid squares should be numbered to guide the user on which color to place where (a "color-by-number" mechanic).
* Users select a color from the palette and then tap the corresponding numbered squares on the grid to fill them.
3. **Rewards & Currency:**
* When a user correctly fills in all the squares and completes the artwork, award them 10 "GameBux".
* The user's total "GameBux" balance must be clearly visible in the app, for instance, on the gallery screen.
4. **Data Storage:**
* Use a database to persistently store each user's data, including their "GameBux" balance and the status (locked/unlocked/completed) of all art templates.
Create a 2D pixel art building game where users create pictures by filling a grid with colored squares.
The app should have the following core features:
1. **Template Gallery:**
* Display a g...