This Plugin uses Alexa Toolbar trick, All your traffic will be considered as user of Alexa Toolbar now each impression will matter and it will boost your Alexa Rank.
If you are not aware of Alexa Toolbar, read below.
Alexa Toolbar is an extension or module to some Browsers which few users have already installed, So for the user who has installed this toolbar in its browser then accessing any website the alexa rank of it will be improved considering that the traffic will go through alexa.
Alexa algorithm is aware of that all users are not using alexa toolbar so a single user with toolbar means many users are accessing the website, So what this plugin trick does is that all your traffic will go through alexa toolbar and it will consider that the visitor has alexa toolbar installed. which means every impression will be considered unique by alexa.
You can use Zenmate Extension to use any country proxy and then access your site if you are targeting any specific country.
Alexa do not just rely on the toolbar traffic, Their algorithm considered several other factors so Boost in traffic is not guaranteed but logical.
This plugin will actually give a competitive edge to your business.
It is totally SEO friendly, 100% safe to use.