1. The plugin doesn't seem to work by adding a "pin it" button to the images on the site. At least it didn't on mine.
2. It claims to be able to automatically re-post WordPress posts to Pinterest. Which would be great, but it didn't work either.
3. But actually, that's not surprising, because it just asks for your Pinterest login information, and there is no mechanism to select which board your pinned post would go on. Which would be necessary information...
Unless you were just trying to steal Pinterest login info.
I hope I'm wrong, and if so, I extend my sincere apologies, and respectfully request an explanation of how this is supposed to work.
In the meantime, I suggest WordPress remove it from WordPress.org.
Regardless, it's main functionality does not appear to work.
FWIW, there is no public API for Pinterest, so an auto-post plugin for Pinterest seems unlikely to work at all, or at minimum, for the long-term.