Okay, I've added this to my wp and I found it easy, simple, & nice but it needs a lot of works to be better!
1st. I'm using a RTL WP and once I activated the plug-in, it re-arranged every thing in the wp cp. it became LTR!
2nd. There is no way to allow only one vote for each visitor! Visitors can vote again and again with every refresh to the page!
These two points are for start... Thanks