Structured Pro is the subscription version of Structured that includes a few extra features. Without Pro, you can use almost every feature of Structured for free, and the app will never include ads or sell your data. However, by subscribing to Structured Pro, you will gain access to these additional features:
Structured Pro is available as a monthly, yearly, or lifetime subscription. The monthly and yearly subscriptions can be cancelled at any time, at least 24 hours before the automatic subscription renewal. To upgrade to Structured Pro, go into the ⚙️ Structured Settings and tap on the Structured Pro button. Then you can select your preferred subscription model and pay via Apple.