Samurai is a GUI for TA4J. It's supposed to make it easier for you to get insights in how to improve your trading strategy. You will be able to use all the TA4J built-in and custom indicators to create your strategies. When you have written a strategy, you run it over a dataprovider to see how it would have traded. At some point, this will also support automated trading. Note that this is still a work in progress application and it is not yet functional enough to be used.