Useful but flawed
First the good news. This app works. You can write & execute Ruby code on your iPad. That is useful. However: When you get an error, all you get is the error message (e.g. SyntaxError) you don’t get any information about where the error occurred forcing you into print debugging. Paste is broken so moving code about becomes an extreme chore. After you run the code the editor jumps to the end of the file. It’s also a bit erratic from time to time. Nothing I can pin down but odd completions, jumps, or inserted characters. The MRuby documentation doesn’t appear to be searchable for contain actual descriptions or examples of the methods listed. It would be nice to have a side-by-side mode.