Shorten.REST - A URL shortener API you can depend on
Ji.Hn - Shorten your links, track, target or rotate them
Pixela - Record and Track your habits or effort. All by API.
Short.io - Short.io makes short links (vanity urls) on your own domain. Free signup, analytics and API. Chrome, slack, zapier and segment integrations.
OFFF - Shorten URLs from the address bar
MailTumble - MailTumble is a service that tokenises email addresses, allowing you to share your lists with third parties.