Our goal is to allow people to use the code and learn from it for any non-commercial purposes. We want to retain the right to earn money from the project (through future in-app purchases, or adding a price to the app for v2). I'd love for this to be a collaborative project, rather than something like Canabalt (https://github.com/ericjohnson/canabalt-ios) which seems like its simply a one-time code giveaway. Is there a license which fits our case, and aside from setting up a public git repo (which I'm in the process of doing, https://github.com/workwithnano/silent_shout), does HN have any other advice for us?