A new release is available in the app store v14.15 which resolves the issue for iOS 13 - https://itunes.apple.com/gb/app/okappy-simple-job-management/id494390368?mt=8
Push notifications are not being received on some iOS devices due to a change introduced in iOS13. We are working on an update. In the meantime please check the job viewed column on the dashboard to see if you’re engineers have seen the job