The Outlook add-in can be used from either the Outlook Web app or the Outlook desktop app to sign documents yourself or send them to be signed by others. 

How do I use the add-in on the Outlook app?

• Open an email with a document attached and click Signeasy.
• Log into your Signeasy account and grant permission for Signeasy access.
• The document will be imported to Signeasy
• In the Signeasy popup, select the Signature type and you'll be taken to the Signeasy interface.
• Fill out your document, or fill in the Signature Request details
• Once your document is signed, you can re-attach and return it to the sender.
• Copy of the signed document will be retained in your Signeasy account

The Signeasy Add-in only available for Business plan users.