BT Grader is a free bubble sheet grading software. There are many bubble sheet grading software and special hardware designed for grading bubble sheet in the market. Most of them are proprietary and requires scanned bubble sheet as input. In contrast, BT Grader is free and has ability grade pictures taken by camera and phone. Of course, scanned sheet is also acceptable. You does not need pricey special scanner. Just take pictures of answer sheets and receive the report in desired format. The software supports grading of multiple version answer sheets.