I was once attempting  to write something like this and had a test version up.<p>Here is the repo:
<a href="https:&#x2F;&#x2F;github.com&#x2F;KonstantinSchubert&#x2F;bitcoupon-public&#x2F;" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;KonstantinSchubert&#x2F;bitcoupon-public&#x2F;</a><p>Somehow I got bored with debugging all the different components, but I still think it has a lot of potential.