Questions, bugs, or ideas? Email [email protected] and I'll get back to you.
On your iPhone, and nowhere else. Nook has no server and no account in the cloud. Nothing you save is uploaded, and nobody but you can see it.
No. Signing in is optional and only puts your name on your wall. You can use everything without it. If you do sign in, you can remove the account any time from You → Account → Delete Account.
Tap the share button in the other app, then choose Nook from the row of apps. You can edit the text, add an author, and pick which collection it goes to before saving.
If Nook doesn't appear in the share sheet, scroll the app row to the end and tap More, then turn Nook on.
iOS decides when widgets refresh, so a new nook may take a few minutes to appear. The refresh interval in Settings is a hint to the system, not a guarantee. If a widget looks stuck for a long time, remove it from the home screen and add it again.
Open You → Export. That saves every nook, including images, to a single .nook file. On the new phone, open that file and choose Import.
Merge adds anything new without touching what's already there. Replace overwrites everything on the device with the file.
Subscriptions are handled by Apple, not by Nook. Open Settings → your name → Subscriptions on your iPhone, or tap Manage or Cancel in Nook under You → Subscription.
If you cancel during the free trial you are not charged. If you cancel after billing has started, the next renewal stops and you keep access until the end of the period you paid for.
Tap Restore on the paywall, or You → Subscription → Restore Purchases. Make sure you are signed in to the same Apple Account you used to subscribe.