But aren't you cluttering your "app" object then? Sure, your interfaces are pretty stable now since you pass "app" around. But now "app" leaks all kinds of fun

But aren't you cluttering your "app" object then? Sure, your interfaces are pretty stable now since you pass "app" around. But now "app" leaks all kinds of functions to all callees, which don't really need all functions declared in "app". If on the other hand your "app" object is quite lean, and follows the behavior of maybe Context in Android, then ignore my above comment, and I would agree with you.