Consider these two simulators, if you want to try the examples in the paper:

1. https://www.research.ibm.com/ibm-q/

This is IBM Quantum experience. Click on "experiment" to start. It has a nice tutorial.

2. http://algassert.com/quirk

I like this one much better, because you can see the internal state of the machine at any moment. And it has much more options and is much faster.