If you are experiencing issues with the Book Crawler app where it remains locked after upgrading from the trial version despite payment, follow these steps to troubleshoot and resolve the issue:

1. Verify Your Payment Status
Check if the payment of $9.99 was successfully processed. You can do this by reviewing your purchase history in the App Store:
- Open the App Store app.
- Tap on your profile picture at the top right.
- Go to Purchased and see if Book Crawler is listed there as a purchased app.

2. Update App to the Latest Version
Ensure that you are using the most recent version of Book Crawler, as updates may fix known bugs. To update:
- Open the App Store.
- Tap on your profile picture.
- Scroll down to find Book Crawler and tap Update if an update is available.

3. Restart the App and Device
Restarting can resolve many temporary issues. First, close the Book Crawler app by swiping it away from the app switcher. Then, restart your iPhone:
- Press and hold the Side button and either volume button until the slider appears.
- Slide to power off. Once off, hold the Side button until the Apple logo appears to turn it back on.

4. Reinstall the App
If the issue persists, reinstalling the app may help clear any corrupted data. Before proceeding, ensure you have your data backed up if necessary:
- Long-press the Book Crawler app icon until you see the menu.
- Tap Remove App, then confirm by tapping Delete App.
- Afterwards, go to the App Store, search for Book Crawler, and install it again.

5. Contact Support
If none of the steps above work, you may need to contact Book Crawler’s support team directly. You can reach them via their official Facebook page, where you’ll find contact options and further assistance: Book Crawler on Facebook - [learn more].

Following these steps should help resolve the trial version lock issue in Book Crawler after your upgrade.