Can I use Android Zello while it running in the background? Zello Android PTT is designed to only work when Zello is in the foreground, to avoid creating problems with other audio apps running. But you can assign a headset buttton as PTT to be able to use Zello while it running in the background. Zello Support October 26, 2016 16:08 Follow Have more questions? Submit a request 0 Comments Article is closed for comments.