Question: Example: when you click a button to upload an image, you get the dialog to choose a file. Then you can select an app you want to choose it. How can I make my app appear in that dialog?

![](https://i.stack.imgur.com/6hHRyl.png)

Answer: 
Add the following intent filters to your Activity where you want the picking to take place:

```
        <intent-filter >
            <action android:name="android.intent.action.PICK" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:scheme="file" />
        </intent-filter>
        <intent-filter >
            <action android:name="android.intent.action.GET_CONTENT" />

            <category android:name="android.intent.category.OPENABLE" />
            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="*/*" />
        </intent-filter>

```

The first one handles an Action Pick, and the second one Get Content.

You may want to change your mimeType to restrict selection a little. The one I provided will put your app in the selector for every type of file.
[simple and complete example code (less than 50 lines)](https://stackoverflow.com/a/15555455/1166727) for app that android will present to the user along with menu list of compatible apps (polaris, browser, etc) when opening a TXT file.

disclaimer: in case user hasnt previously determined a default app 

note: TXT may be changed for other extensions, always paying attention to mime types.