Why does shadowClipboard try to contact a webserver during startup? 

It tries to determine if a new version of the application is available. 
A request is sent to the stupidfish23.com server, which in turn returns the latest build number for shadowClipboard. This data is then processed within shadowClipboard on your own Mac. If the version on the server is newer than your currently installed one, shadowClipboard will inform you of this.

This happens twice during startup. If there is no internet connection, shadowClipboard will assume the current version is the latest one.

 NO user data is sent over the internet.

If you want to know about our privacy policy, please go to 
http://www.stupidfish23.com/privacypolicy.php

If you still do not feel comfortable with this there are applications that filter network operations for given applications.

Should you have additional questions, please send a mail to privacy@stupidfish23.com