One of the best free option for providing cashback

So far, I liked this plugin for its simplistic approach to providing relevant UI and functionality.
The agileness with prompt support within a day will surely increase reputation for this plugin as well as it plugin developer(subrata).
I Will be waiting for its more features, also may go for its Pro version if released after it provides all basic cashback functionality to its optimum level first.

You can go for this, as it worked fine with latest wordpress