I deliberately reduced the extension to two methods to propose to MIT their integration into the core of App Inventor in order to introduce the concept of regular expression to a large number of people.
The following package contains:
-extension: fr.danielm.Xreg.aix
-documentation and examples file: Regexp.html
-documentation and examples file: RegexpReplace.html
If you are posting an extension then it should be in the Extensions category.
Also
unlisting for now....