Gmail Tasks now on Mobile
Google does not have an independent To-Do application. But they do have a tasks feature inside Gmail through Gmail Labs feature.
Google is now enabling their users to check their tasks from mobile devices directly.
They can access the Gmail Tasks through a direct link that works on mobile browsers. [...]

Google adds Tasks feature to Gmail through Gmail Labs
Google has finally added a To-Do feature to Gmail.
They call this feature Tasks and it is now available through Gmail Labs.
It is not very user friendly at the moment though.
Users get a link on the left sidebar which opens up a chat like window at [...]