Bookends for iOS is a part of Winterfest 2023, the festival of artisanal software. 25% off for Standard and Pro in-app purchases.
The Standard in-app purchase is already discounted on the App Store.
To activate the discount for the Pro Features Yearly, please follow this link in Safari for iOS:
https://apps.apple.com/redeem?ctx=offer ... ERFEST2023
P.S. If you are a currently subscribed user and plan to continue using Bookends for iOS - it's a good chance to prolong your subscription for another year at the discounted price $7.49. Later next month the cost of in-app purchases will increase to $14.99 each.