In a recent announcement from SquareUp we found that some adjustments will need to be made to your device before the Square Register payment app will work properly.
To do this:
- Go to Settings > Privacy > Microphone
- Turn on the Square Register slider
- Relaunch Square Register and swipe away.
If you have yet to make the iOS 7 update, your app will function normally. When you update, follow the prompt to allow microphone access the first time you open Square Register.