It wasn't clear that I needed to sign into Evernote in order to access to certain sharing options, such as Copy and Share URL, Direct URL image, etc. It's confusing because you do have sign in options once opening Skitch, but just not certain ones.
My advice would be to:
1) Change the button prompting you to sign in to Evernote to say "Sign in to save and share with Evernote".
2) Highlight in the Skitch/Evernote documentation that not all sharing options are available until you sign in to Evernote. It was confusing reading this guide that said I had certain options I didn't see
