Remotely execute code via Heroku
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.