I'm unable to update NotchNook

Just to make sure, please check if NotchNook is in the application folder. If it’s not, close NotchNook and then move it to the applications folder. After that, try updating it again.

If that doesn’t work, you can try downloading NotchNook from https://lo.cafe/notchnook. The updater in your version might be broken, so you’ll need to download the latest version manually