To change your app icon to your team's, first log in to the mobile app. 

Click on Account from the bottom navigation bar, then scroll down and click on App Icon. Next, click on Set Icon for your team's icon. Click OK to save.  

The icon for the app has now been updated on your iPhone so your team's icon will be displayed.

Note: Android users do not have the ability to update the icon to their team's icon based on limitations from Android. Check back as this may change in the future.