It is a completely free app and it can be placed anywhere on the site. Its a simple code that you need to copy and paste into the locations where you want it to appear on your website. Their support is superb as they responded to my questions within few hours!
Before you do complain about to developers about free apps... almost all free apps will include a branding because other start-up stores would reference sometimes reference other stores to find apps. Negative reviews to these developers without asking for support or complaining about branding when they made this app free to you... it's just plain wrong to give a 1 star review!
Keep up the great work devs!