This component uses the Quaggajs library to read a barcode. It only implements reading barcode from a file or photo library as live stream is not supported in iOS. It uses a iframe and post message to for Locker security compatibility. Install the component in your org and then use the BarcodeScannerComp in the lightning app builder and surface in Salesforce1 as a navigation item. You can also use this component as quick action.