The Lambdalator app is a simple online Lisp interpreter that lets you type in Lisp expressions for evaluation.

It uses the newLISP dialect of Lisp, which is easy to use and well-documented. The primary aim is to provide calculator-style functions for use when the simple calculator won’t do.

To sum a sequence of numbers, for example, enter them like this:
(add 1.2 1.24 125.23 125.23 12.4) and then tap ‘evaluate’. The result, and a record of the expression, are shown. If you make a mistake, or want to change the numbers, tap ‘again’ and edit them.

There are dozens of useful functions available - from trigonometry to statistics, from mathematics to financial, from strings to lists. Only the process and file-management tools are not needed on this web version. Try with TestiPhone