Perhaps slightly off-topic: The name, GmailSharedTasks, doesn't look like one that Google's legal department would agree with. Your brand/product name incorporates a Google trademark. It might have been better to call it "SharedTasks for Google Tasks™" or "SharedTasks for Gmail™".

See "I'm a developer and used Google's developer products/tools to create a new product. Can I use the Google name?" on http://www.google.com/permissions/faq.html