There is no killer app for Bitcoin at the moment, we'd all be millionaires by now.
That said, there's no shortage of development, investment, and promotion going on that could prevent that killer app from launching.
There's the wallet apps, the hardware wallet devices, the Xapo debit cards...but we don't quite have our instagram, our tinder, our Uber, our Facebook just yet.
Perhaps once Paypal launches with Bitcoin payments or another brand new application that raises awareness as well functionality, it'll pique the interest of the masses.
But at the moment, no killer app.