If you are using another service on a different site and would like to add it to your website, you might be able to with the embed code tool.
First, check if your service offers embed code or iframe code that can be copied. For example, facebook provides embed code you can use to display your feeds within any website page.
Once you have the code copied, come back to your simplebooklet.
Navigate to the page you want to add the code.
Tap the CODE button.
Tap Embed Code in the menu options.
Paste your code into the code window.
This will add your embed code content into a content container on the simplebooklet page.
You can then resize the container to better fit and match your content to fit your page.