Grape works without an account. You sign in for the things that need a server: the Sync and Pro subscriptions, cloud sync, sharing and Grape AI.
Signing in
Sign in from the Account tab in Settings: with Apple or Google on the phone, and with Google on desktop. There is no separate password to manage. Subscribe to Pro on desktop signs you in on the way to paying, see Get started with Grape.
On desktop, Already have an account? Sign in opens grape.cool in your browser, and the Account tab says Waiting for your browser while you log in with Google there. Once you are in, Grape comes to the front signed in on its own, and the browser tab says you are signed in and can close it. If that browser is already logged in to grape.cool, this happens straight away. Cancel next to Waiting for your browser stops the wait, and so does leaving it for 15 minutes.
If the browser says it cannot connect instead, go back to the grape.cool page, choose Open Grape App and let the browser open Grape. Older versions of the desktop app sign in this way every time.
What signing in changes
With a Sync or Pro subscription, sync starts keeping your devices in step, and on Pro Grape AI becomes available as well. With Lifetime, your devices keep in step once you connect your Dropbox or Google Drive in Cloud Sync. Invites sent to your address wait in Settings under Sharing, ready to join. The sample notes that shipped with the app are cleaned up on the first sync if you never touched them.
Signing out
Sign out from the same tab. On desktop and on the phone Grape then asks what to do with the notes on the device: keep them, or delete everything from it. Keep is the answer on your own computer or phone, delete is the answer on one that is not. Everything means the notes and their files, the settings, with your AI models and API keys among them, and the backups, so the next person to sign in finds the device the way a fresh install leaves it. Deleting asks once more before it runs, and it only empties that device: anything that was synced stays in your account and comes back when you sign in again. On Lifetime, signing out also disconnects Dropbox or Google Drive on that device, and what is in it stays there.
On iPhone and iPad, the notes you keep stay in Spotlight, apart from the folders and notes other people shared with you, which leave it with the account. Deleting takes everything out of Spotlight too.
Account versus app
Deleting the app or signing out never deletes your cloud data, and deleting your account never deletes the notes on your device. The two live separate lives on purpose.