Been using it on a 16 GB phone for years (on an iPhone 4 and now iPhone 5). Sure, it ends up taking up more and more space as far as caching, but uninstalling the app and reinstalling it every month or two takes care of it fairly quickly. I agree it's not how it should be and it should be done better as far as clearing out the cache sooner and/or more often and/or providing an option in the app to do it, but at least the workaround to clear it (uninstall and install) isn't much of a hassle. Similar kind of thing applies to a number of other apps as well.