[mancerayder]

Here's an idea. Ethereum smart contracts to short bitcoin. You borrow my BTC for 30 days, with a 5% fee. Someone could make a killing off of that idea.

[chrdlu]

https://medium.com/dydxderivatives/introducing-dydx-2d0f0f32...

Note: I'm not affiliated with that project, but I did see them present yesterday at Token Summit and it looked very interesting!

[colecut]

This is more of a general purpose app, but would work.

https://gofreakingdoit.com/