1. An aimer accessory for a mobile device, the aimer accessory comprising: a body configured for being affixed to the mobile device, the body comprising a collimator terminating with a grating disposed in a distal portion thereof, the grating configured to receive light from a lamp of the mobile device, and to generate a light pattern on a surface containing a barcode; wherein registration of the light pattern and the barcode in a scan area precedes capture of a barcode image by the mobile device and enhances the ability of the mobile device to capture the barcode image; wherein the aimer accessory is configured to operate, selectively, in blind mode scanning and in targeted mode scanning; wherein the registration occurs, in the blind mode scanning, on a detection of the light pattern and the barcode in a viewing angle of a camera of the mobile device; and wherein the registration occurs, in the targeted mode scanning, on a detection of the light pattern hovering over the barcode in the viewing angle of the camera of the mobile device.