Not to worry! In some cases, it may take time for the device to get the updated app that reflects the new free price. Rest assured that if you subscribe now you will not be charged!
You can see this new free price in the app immediately by taking the following actions:
Restart your device to receive the updated Call Screener app. Once the device restarts, it may take a few moments for the updates to be reflected in the app.
Go to the App store to update the app. The app will reflect the new free price.