This is a customizable Calculator in which you can set your own GPA Criteria and save it for future uses.
You can choose your own set of grades,their points on the scale and range of marks in which these grades are awarded.
Then you can either enter your marks or Grade along with Credit Hours and Can view the total Grade Points.
It also includes a CGPA Calculator which you can use to calculate your CGPA by entering the GPA from previous Semesters and their total Credit Hours.
This app is available on Windows and Windows Phone Store