Custom Formulas (free)

This powerful app lets you create your own custom formulas and then perform computations using them by prompting you for the input values.

Note that this free version is limited to storing only one category and one formula group. Upgrade to the paid version to remove these limitations and to remove the ads.

This app is easy to use, but unlike simpler apps, multiple entered values can be fed into multiple formulas and multiple output values can be displayed. The output of one formula in a group can be fed into the next by using the same variable name.

Related formulas can be grouped into categories to make them easy to find. e.g. Maths formulas, Surveying formulas, Loan interest formulas etc.

The order of variables displayed to the user can be changed, as can the number of decimal digits of precision shown in the output fields.

One example formula, compound interest, is pre-installed with the app.

A formula group can be exported to a text file. Other users of the app can then import it, allowing your creations to be shared. An open forum where you can share formulas is available here: https://groups.google.com/forum/#!forum/custom-formulas

Note: Do not use "e" or "pi" as variable names since these are pre-defined constants. This app uses the JFEP library. See the following page for the list of supported functions: http://jfep.sourceforge.net/Syntax.html (Plus int(), round(), ceil(), and floor() have also recently been added).

On-line help for the app is available here: http://www.binaryearth.net/CustomFormulasHelp/