Xero rails application built using xeroizer gem. This can be used to perform OAuth 3-legged.
Xeroizer
https://rubygems.org/gems/xeroizer
This is a rails application and so the after the 3-legged auth is complete, a web page is shown with the oauth_token, oauth_secret, oauth_verifier values.
Watch our project https://github.com/indykish/deccanplato.git where a Live cloud is getting built.