Simple app, simple policy.
OctoNote does not persist any note or profile data to your device. OctoNotes is a GitHub OAuth App, meaning OctoNotes that you save in the app are saved as GitHub Gists on GitHub under your GitHub Profile.
About OAuth Apps
GitHub Privacy Statement
Your profile on OctoNote is your Profile on GitHub. As a GitHub OAuth App, OctoNote authenticates as you to enable viewing your GitHub Profile and the viewing and editing of Gists.