Tweetapp is a framework developed by @tav for creating Twitter applications on Google's App Engine, utilizing Twitter's beta OAuth support. The framework has received positive feedback from Twitter's API lead, @al3x, who praised it for its innovative approach. Chris Wanstrath, known as @defunkt, highlights the tool's potential for developers interested in building Twitter-based applications, emphasizing its cool features and thanking @tav for sharing the creation with the community.