Hi! I see that the GHIN app is not opening on your Mac laptop or your iPhone. Just to make sure I’m on the right track, when you say "won’t open," does the app launch at all and then immediately close, or does it simply not respond when you try to open it? Also, are you seeing any error messages?

In the meantime, here are some basic steps we can try on both devices:

On your iPhone (running iOS):
1. Force close the GHIN app: Swipe up from the bottom and pause slightly to open the app switcher, then swipe the GHIN app off the screen to close it.
2. Restart your iPhone completely by holding down the power button and sliding to power off, then turn it back on.
3. If it still doesn’t open, try deleting the GHIN app and reinstalling it from the App Store. This often resolves app launch issues.

On your Mac laptop (OS X 10.15.7 Catalina):
1. Quit the GHIN app completely if it is running (right-click on the app in the Dock and choose Quit).
2. Restart your Mac to clear temporary system glitches.
3. Check if you have the latest version of the GHIN app installed for Mac. If not, uninstall and reinstall the app from the official site or the App Store.
4. If the app isn’t opening and there’s no response, try running the app while holding down the Shift key to see if it launches in safe mode (some apps support this to bypass problems).

Could you let me know what you tried or if these steps help? If the problem persists on either device, I can guide you through more detailed troubleshooting.

Are you satisfied with this approach so far?