> For the complete documentation index, see [llms.txt](https://caseytechschool.gitbook.io/app-development-using-mit-app-inventor-platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://caseytechschool.gitbook.io/app-development-using-mit-app-inventor-platform/tutorial-1-image-hide-and-seek/building-your-first-mobile-app-app-logic.md).
# Building your First Mobile App: App Logic
The app logic is responsible for toggling the visibility of the image and updating the button text accordingly. Follow these steps to implement the logic:
App logic
1. Navigate to the **`Blocks`** tab above the **`Properties`** panel.
2. Click on **`Button1`** in the `Blocks` panel and drag the **`when Button1.Click`** block.
3. Drag an **`if then else`** block from the **`Control`** section into the **`when Button1.Click`** block.
4. Drag an equal block from the **`Logic`** section and drop it into the if statement.
5. Use the **`Button1.Text`** block from the **`Button1`** section, placing it in the first section of the equal operation.
6. Drag an empty text block from the **`Text`** section into the second part of the equal operation. Type *Hide* in the empty block.
App condition
7. Click on the **`Image1`** block and drag and drop **`set Image1.Visible to`** on your screen. From the **`Logic`** section grab the **`False`** block. Connect them together.
8. Similarly, click on the **`Button1`** block and drag and drop **`set Button1.Text to`** on your screen. From the **`Text`** section grab the empty text block and type `S`**`how`****.** Connect them together.
9. Move these two blocks inside the if statement.
Completed if block
10. Right-click on the first set block, choose **`Duplicate`**, and move the duplicated block inside the else statement. Change **`False`** to **`True`** and **`Show`** to **`Hide`**.
11. Duplicate the other block, move it into the else statement, and change the text to **`Hide`**. The final code is as follows:
Final code
12. **Congratulations, you are done!** Test your app to see the logic in action.
