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