How can I use Unity loading indicator in a mobile app?

I want to use Unity loading indicator (spinner) in a mobile app, i.e. I want to show it when my app is calculating something. How can I do it?

The indicator is available since Unity 3.5 and can be reached via the Play Settings. Select the android platform and there “Resolution and Presentation”. There’s a drop down list to choose the loading indicator.

Handheld.StartActivityIndicator()
Handheld.StopActivityIndicator()