Scribd: Upload a PDF and get embed code to insert it on your webpage. Hyperlinks in the PDF are clickable in the Scribd widget.
Nearpod: Lessons in Nearpod can be embedded. Find the embed code by clicking a lesson's Share button.
Padlet: Padlet walls can be embedded. Just be sure to turn on Moderation (by clicking Share) for the wall so that you can approve posts before they are viewable by everyone. Get the embed code by clicking a wall's Share button and then choosing Share/Export/Embed.
Buncee: Buncee provides a multipage canvas where you can add photos, drawings, text, YouTube videos, and weblinks. The paid version allows for audio recordings.
Mixbook: Create a book with your photos and text. When viewing a book, scroll down the page and you'll see the embed code that you can copy. No purchase is necessary to embed. The site and widget require Flash.