PowerSchool offers an excellent student information system, but when importing student data from a text file, it, as one would expect, overwrites current values with the new values. You may not want this when importing student standardized test scores into custom fields because you want to only see their highest value (such as S.A.T. scores).
Best Test solves this dilema. You export the current custom field's value from Power School, import those as well as the new test scores into Best Test, and it will create a new importable text file, selecting the higher of the two scores.