The application does require permissions that may be deemed too invasive by some. For example, to paint a note on a web page (most basic feature of this application), the extension needs to have the permission to access and modify the underlying page data to insert the code for the note.
Currently, the app requires the following permissions:
"storage", "bookmarks", "contextMenus", "tabs", "<all_urls>", "downloads", "clipboardRead", "clipboardWrite", "identity".
More information can be found here: https://developer.chrome.com/extensions/permission_warnings
However, for your information to be accessible by WPSN, the application would have to "phone home" which this one doesn't. The source code is visible to all and with a little know how, the application can be inspected by anyone to validate those claims.