Aimer accessory for capturing a coded image

An aimer accessory for a mobile device and method of use is provided. The accessory includes a body configured for being affixed to the mobile device. The body includes a collimator terminating with a grating disposed in a distal portion thereof. The grating is configured to receive light from a lamp of the mobile device and to generate a light pattern on the surface containing a barcode. Registration of the light pattern and the barcode in a scan area enhances the ability of the mobile device to capture a barcode image. Registration may be configured for blind or target mode scanning. In blind mode, the registration occurs on detection of the light pattern and barcode in a viewing angle of a camera of the mobile device. In target mode, the registration occurs on a detection of the light pattern hovering over the barcode in a viewing angle of the camera.