This isn't really the developers fault and he doesn't really has that access to your full account. I develop an app which syncs with Google Tasks (I'm also the one who posted in the Tasks Google Group posted above).
I only request access to Tasks, but after using the reveived accesstoken (which is only received if the user accepted it in this window code.google.com/intl/de-DE/apis/tasks/images/Android_Auth_Dialog.png) both entries appear. I tried to use the token to access other things, but this doesn't work. I don't know why this entry appears. Even the «Android Login V1 — Manage your Tasks» entry is useless, because revoking the access doesn't change anything on app-side. After revoking access it just reappears next time the token is used, the user doesn't have to grant access again.
