You can upload files (including OneNote, Word, Excel, and many, many more file types) directly to the Files tab in any channel. Just click Files at the top, then click Upload. To create a new file, click New.
While you can't add existing notebooks, you can add new ones in new tabs.
You can upload files in the desktop or web app and view them on your mobile device any time after that.
Emoji are a great way to add some fun into your communication! To send an emoji in a message, click Emoji beneath your compose box. From the emoji gallery, select the emoji you want or do a keyword search at the top of the gallery to find something specific. Once you've selected the perfect smiley face, all you have to do is click Send .