Fomcal is a calculator to calculate quickly with formula inputted already.
Since you can register formulas used in daily routine by yourself, there is no need to search or to develop the dedicated calc app. Fomcal can show descriptions and a figure, about formulas and variables.
Tap "+" button for starting a new formula definition. You can use the formula after the title, variables and equation are described. An explanatory diagram can be loaded from album. Description of formula can be also registered. Please refer Grammer of Fomcal for the detail of formula definition.
Titles of formula are listed on the top page. A calculation page will be open when a item of list is tapped. Export/Inport feature of formula list will be available after purchasing "Enhancements".
Please replace [AT] to @.