The easiest way to add and manage all the Woobox apps on your Page is through our App Dashboard (log in now to access your account). This can be done with a free account, just sign up here if you haven't done so already and get started right away!
Once you've logged into your account, you'll just want to go to the Static Tabs section via the main navigation bar, and then click the Create a New Tab button in the upper right corner of the screen, and select the type of app you'd like to add from the list of options.
Alternatively, you can go to http://wooboxtab.com and install more custom tabs from there. If you've already installed your first tab, you'll want to make sure you click on one of the icons below the big green "Install Page Tab" button to get additional tabs for the same Page.