An appcoin is a cryptocurrency that is designed specifically to power a user application, rather than to just be a means of exchange and store of value. One of the beautiful aspects of private currencies (or private anything really) is that it doesn’t have to be one-size-fits-all. We can have coins with attributes that work better for smart contracts and coins that work better for large transactions between banks and coins that work better for a hundred million people to each pay a penny to watch a music video.