The appcache will cause some confusion in your development workflow, because it hides Meteor's auto-updating features. When you turn off the server component of your app, the client portion in your browser will continue working. This is a good thing! But, you don't get the immediate feedback that your app has been turned off, or that there have been updates.
Try using Chrome's Incognito Mode when developing your app, because it doesn't use appcache.
GroundDB doesn't work particularly well with IronRouter.