Email pawelferchmin@gmail.com. Include the pull request link and, if you can, the text of the skim check on it.
A file I need was hidden. Add a ! rule for it
to .github/review-ignore in the repository, or unmark it in
GitHub. Files with review comments are never hidden.
Nothing is hidden for me. Check that you have authorized Skim and that the App is installed on the repository. On a private repository, the account's plan may be full: the check says so under "Plan limit".
How do I stop it? Revoke it under GitHub → Settings → Applications. Your data is deleted when you do.