An aimer module for a mobile device and method of use can assist in capturing a barcode image. The aimer module can receive light from a lamp of the mobile device and generate a light pattern on the surface containing a barcode, including through the use of a grating, a configuration of mirrors, light pipes, or other methods for bending or controlling the lamp source of the mobile device. Registration of the light pattern and the barcode in or near the scan area can enable a camera of the mobile device to capture and decode the barcode.