Notion to Mobile Cards by CoDo alternatives

I like knowing that the link has been clicked. It only takes a few moments to enter your note, generate a link, and send it off to whomever you want to view it. It can only be viewed once, and then anyone who clicks the link will see the message "This message has already been viewed." I use this to share passwords, credit card info, and other private info I don't want sitting in an email or accidentally shared from an instant message.