The evening of September 12 we issued a new release to the App with Square that addresses the underlying cause of the issues you may have experienced with credit card sales. This issue did not impact iPhones. We again apologize for the inconvenience we've caused those of you who have Android devices.
The update to app version 1.5.6 is required to sign in, which is available in the Google Play Store. No update is required for iPhone users in Apple's App Store.
Thank you so much for your patience.