Hi there! I'm here to help you with that issue you're experiencing with the FreeStyle Libre 3 app not opening. I know how important it is to stay on top of your health data.

To get started, can you share if you've noticed any specific error messages when trying to open the app? Also, have you made sure that your iPhone is updated to the latest version of iOS? This info will help me figure out the best solution for you!

When I touch the icon, it just flashes & then goes back to my Home Screen.

Thank you for providing more details! It sounds like the FreeStyle Libre 3 app is crashing right after you try to open it. Let's go through a few troubleshooting steps to see if we can resolve this issue:

1. Force Close the App:
- Swipe up from the bottom of the screen or double-click the Home button (depending on your iPhone model) to open the app switcher.
- Find the FreeStyle Libre 3 app and swipe it off the screen to close it completely.

2. Restart Your iPhone:
- Press and hold the power button (and the volume button on some models) until you see the slider.
- Slide to power off your phone, then turn it back on once it's completely shut down.

3. Check for App Updates:
- Open the App Store.
- Tap on your profile icon at the top right to access your account.
- Scroll down to see if there’s an update available for the FreeStyle Libre 3 app. If it is, tap ‘Update’.

4. Reinstall the App:
- Go to your Home screen, press and hold the FreeStyle Libre 3 app icon, and tap 'Remove App'.
- Confirm by tapping 'Delete App'.
- Then, visit the App Store, search for the FreeStyle Libre 3 app, and reinstall it.

5. Check for iOS Updates:
- Go to Settings > General > Software Update.
- If there's an update available for iOS, install it.

If these steps don’t work, sometimes user reports indicate that issues can also arise from recent app updates, and there may be a patch available. You could check discussions on Reddit to see if there are recent updates that have fixed similar issues for users.

Please give these steps a try and let me know how it goes!