# App List Builder

App lists are collections of Chartboost app IDs you can use to exclude, but not target, low-performing or unwanted games from your campaigns. This setup is not required to run your campaigns, but it may improve your campaign results.

Visit our [app filtering page](/en/faq/advertising/) to learn more about how to identify low-performing games.



## Creating an App List

Navigate to the [app list builder](https://platform.chartboost.com/tools/lists/app-lists).

1.  Enter a name for the list and pick  **iOS**,  **Android**, or  **Amazon**  from the  **Platform**  dropdown. You’ll need to create separate app lists for each platform.
2.  Click  **Choose File**  in the  **Select File**  field to upload your list. App lists must have a .csv extension, contain fewer than 800 app IDs, and should contain nothing but a single list of app IDs separated by line breaks.  We recommend using Excel or other spreadsheet editors to export your single column of IDs in .csv form.
3.  Hit  **Save**, and you’ll see your new list appear in the page’s lower section.

You can also overwrite, edit the name of, or delete an app list from your account. See the actions column.



## Using App Lists

Once you’ve created an app list, you can apply it to your campaigns via the **Edit Campaign** page’s **App Filtering** tab.

After clicking the name of your app list, you’ll see its entries populate in the same section, after which you can add/remove apps as needed.



## Additional Notes

-   Excel has a 1 million row limitation, but you can create a text-based CSV if you need to add additional devices to your list
-   Uploading a new file to an existing list will replace the original list
-   Downloads stop working after 7 days
-   You cannot delete lists that are currently used in active campaigns