+5
Remotely execute code via Heroku
This is similar the Remote source code compilation idea, but instead of ideone, it would use Heroku. Heroku currently supports Ruby, Javascript, Python, Java (so any language on the JVM like jRuby and Clojure).
Once you have the git integration done, deploying to Heroku should be as simple as a git push command. You could even use the "heroku run bash" as a remote terminal window for your code or "heroku run <insert script name>" and pipe the output to the iPad.
Users could setup their own Heroku account and Textastic could add a Heroku API Key config. That way each user will pay for their own usage.
Customer support service by UserEcho
https://www.nitrous.io is also another alternative. It supports spinning a ruby, go, node.js or python VM and it can launch your app or allow you to ssh to the box and edit code. This might be awesome for writing a script or some code and then being able to execute it via nitrous to get the output or to debug it.