FreeDev apps support calculated attribute type and can implement simple formulas to demonstrate this feature. FreeDev demo app includes Basic Calculations entity which shows how to use calculated attributes in your designs.
Calculated attributes are derived from other attributes. The calculation formula is defined in the formula field. For example, the following formula sums up 3 attributes;
You can use the calculated attributes in your app layouts like any other attribute type. The related article section shows demo apps which use the calculated attributes. Advanced calculations require ProDev account.