"Bitcoin Balance Doubler"
for Android/iOS/PC/Mac/etc 

No speculation on this?

When you use your credit card with Circle, it's a cash advance as far as the credit card company is concerned which translates to high fees.

The "iPhone Money Miner" - Use your iPhone to generate free money!  Yes, you really did read that correctly.  As smart phones continue to get more and more powerful, why not use this power to put it to work for you!  Even with your phone on standby, it can be working on complex math problems in the background.  These math problems are the lifeblood of so-called "crypto-currencies", and they need machines to do these math problems.  They need so many machines to do them, that they are willing to pay you for your time!*

* Disclaimer: data rates apply, battery life may decrease, but you get paid to do this while walking around the mall!

Now available in the app store... only $0.99

Social media payments? You mean you pay people via facebook or something like that using bitcoins?

Mining for BitCoins with your 4G or 5G.
Games to earn BTC.
Music for BTC.
Dunno. Figure it out yourself.

How about adding a small feature to that killer chat where you earn satohi's or bitcoins for chatting? Wouldn't that be nice?

So interesting that everyone's answer to my question about a killer app is something that makes them money.  Or maybe that's just the kind of folks that hang out on this forum (myself included).  But if you were using an app like that, wouldn't you just trade the BTC for fiat?  I'm wondering what might come up that causes people to want to buy BTC in small batches, transact with it, and then top up.  Like a prepaid cell phone.  Remember when everyone opened a Facebook account (eventually even the holdouts) because they couldn't do what they wanted to do without it?

The killer app will be the current fiat system collapsing with capital fleeing in panic. Some of that capital will flow into Bitcoin.

Apart from capital flight, I imagine a simple easy-to-use Bitcoin payment device with NFC (essentially like a credit card, but with added sending functionality) would be a huge step in the door.

But maybe there will not be a killer app at all. Bitcoin might just grow its way to Mr. and Mrs. Joe organically...

ya.ya.yo!