The first and obvious reason why I was enforced to develop another toy was actually the fact that none of the GMail notifiers work right. Well, each of them worked in its own way making me really frustrated.
half-functionally, but still wanted to utilize it.
The investigation I made against GMail API proved it would be impossible to make a good notifier using their promoted ATOM and XMPP protocols because of moronic implementation. While they work with "conversations" instead of emails there's no way to know how many unread emails are in the inbox.
So GMail on Rocket had begun: it should have accurate message counter, use push notifications, support labels and run as system wide Mac OS X application. Sounded easy.