Albrecht offers a straightforward and yet comprehensible method to calculate grades. It's an iOS App I developed together with Raphael Jecker in 2015.
Nowadays teachers don't follow strict linear scales (Rule of Three formula): For example, even if the class performed very badly at a test, the teacher will not want every student to be insufficient. Often it is required by the school to reach a certain grade average. The linear scale doesn't always help out, but not using it can make calculation challenging if you're not a math teacher.
At the heart of Albrecht and at the top of the app's screen is a three-step scale to map the highest and lowest scores to corresponding grades. If however a linear scale doesn't do the work, a bend can be applied by defining a value pair in the middle. Below the app offers a visual allocation and displays the average grade.
In the following video, you can see the app in action – unfortunately it's not available in the App Store anymore.
To promote the app and explain its functionality a dedicated website was created: