I tried out this project with similar aims in the past: https://github.com/rainforestapp/heroku.json but it wasn't quite enough to get an app up and running.
My approach though was having a Chrome extension to add that button on any GitHub repo. Clicking it would create the app, clone it and push it out to your own instance.
Some things slowed me down though. For example the Heroku API doesn't play well with requests made with XMLHttpRequest inside the browser, so I wrote a simple proxy for that purpose. I started working on a Heroku app that would do the git cloning but haven't had much time on it.
With curl, the doc says to use a blank username and the token as password in Basic Auth. When I do that with XMLHttpRequest, the token is completely ignored and the main site's cookie is used. There is no way not to pass the cookie with XMLHttpRequest unfortunately, so I would have to rely on if the user is logged in or not. That would bring other problems: I could only use the API for one account at a time for example, and I would have to add checks to see if the user is logged in, etc.
So my work-around was to write a proxy that would just pass around the requests to Heroku and the response back to the XMLHttpRequest client. (https://github.com/Timothee/Passeplat) With it, I can make the same requests I would make to https://api.heroku.com but instead make them to mypasseplatinstance.heroku.com.
Making this a Heroku-ready app is of course not a coincidence: my plan is to use my Heroku instances (the proxy and the yet-to-be-written git clone) to bootstrap a couple of Heroku instances with the user's own Heroku account. Then the extension would use these to start up other apps. I like the bootstrap idea: it's like compiling a compiler. :)
I'm now realizing that it might even be done with a buildpack… I'd have to look into that. (that would remove the need for that second "git clone" app) Hum, I'll really have to look into that! That could make things much easier and cleaner. (and also cooler)
There would still be the issue of specific configurations and add-ons to deal with, but that shouldn't be too hard if the rest is done.
edit: I haven't checked if this is still a problem with today's announcement. Also, I contacted Heroku support about it, but they only suggested I use a proxy.
To me, the API endpoints should behave the same way in a browser as with curl without ever redirecting to the login page.
But, once again, it might have been fixed in the meantime… I haven't tried recently.
git clone https://github.com/whatever; heroku create; git push heroku master heroku config:set SECRET_TOKEN=`openssl rand -hex 20`
heroku run rake db:migrate
heroku addons:add scheduler
Open the scheduler webpage and add an hourly task
heroku restart