Ability to export signatures or have the signatures centrally stored in 365 cloud. This is really quite necessary for migrating users between machines. @LukeHamburg has summed it up perfectly here:
Ernst von Harringa commented
Instead of waiting for the Dev team, I found this:
Here's the process I used with this app:
1. Copy signature over to Microsoft Word including images. Note: good luck with the image placement in Word, that always drives me nuts.
2. Save the doc as "webpage, unfiltered". Select Yes at the warning prompt. This will generate a .html file.
3. Open that .html file in Chrome, and right-click to select "View Page Source"
4. Copy all the html code. Note: any images need to be stored on a webserver in png/jpg and using https:// to prevent annoying warnings. An SVG file won't work for instance.
5. Paste this into the "HTML Email Signature - Outlook" app.
6. I kept Outlook closed during the process of applying the signature. It works great!