Sparrow has the luck to have a community of a lot of great folks and awesome programmers.
Many of those have already created numerous add-on classes, source modifications, Xcode templates and even complete open source games with and for Sparrow!
To make it easy for every Sparrow user to find those contributions, I want to invite the creators to list their contributions here. Please write a short summary about the project and add a link to its main discussion thread and where it can be found.
Please don't start discussions about the contributions here, but keep them in separate forum threads! This thread should just be a clearly arranged way to find them.