Ad free and enhanced version of the awesome Final Grade Free app!
This all lets you put in your current grade, the grade you are hoping to get after your final (or any other test) and the weight of the test as a percent.
Inversely, you can put in your current grade, the minimum grade you can get to receive an A (or B, C, etc) in a class, and the app will give you the lowest score you can possibly get on the exam, and still receive the desired passing grade.