Hi,
great to see an open source app being built on top of the API.
I would suggest that you publish your source code with our demo API key (oauth_consumer_key=YOUR_KEY_HERE, oauth_consumer_secret=YOUR_SECRET_HERE) and provide a link to the API sign up form for anyone wishing to host the app themselves.
The problem with making API access credentials public (whether it's your own key or the above demo key) is that they're fully open to abuse. If someone uses the key in an attempt to scrape the API then you're very likely to hit the request limits or the key might even end up getting blocked altogether.
Let us know if you have any further questions and also when you publish your app!
Thanks
Filip